diff --git a/make/modules/java.desktop/lib/ClientLibraries.gmk b/make/modules/java.desktop/lib/ClientLibraries.gmk
index a69b65180d7..5cb7501b6f4 100644
--- a/make/modules/java.desktop/lib/ClientLibraries.gmk
+++ b/make/modules/java.desktop/lib/ClientLibraries.gmk
@@ -236,7 +236,7 @@ ifeq ($(ENABLE_HEADLESS_ONLY), false)
       DISABLED_WARNINGS_gcc_dgif_lib.c := sign-compare, \
       DISABLED_WARNINGS_gcc_jcmaster.c := implicit-fallthrough, \
       DISABLED_WARNINGS_gcc_jdphuff.c := shift-negative-value, \
-      DISABLED_WARNINGS_gcc_png.c := maybe-uninitialized unused-function, \
+      DISABLED_WARNINGS_gcc_png.c := maybe-uninitialized, \
       DISABLED_WARNINGS_gcc_pngerror.c := maybe-uninitialized, \
       DISABLED_WARNINGS_gcc_splashscreen_gfx_impl.c := implicit-fallthrough \
           maybe-uninitialized, \
@@ -247,7 +247,6 @@ ifeq ($(ENABLE_HEADLESS_ONLY), false)
       DISABLED_WARNINGS_clang := deprecated-non-prototype, \
       DISABLED_WARNINGS_clang_dgif_lib.c := sign-compare, \
       DISABLED_WARNINGS_clang_gzwrite.c := format-nonliteral, \
-      DISABLED_WARNINGS_clang_png.c := unused-function, \
       DISABLED_WARNINGS_clang_splashscreen_impl.c := sign-compare \
           unused-but-set-variable unused-function, \
       DISABLED_WARNINGS_clang_splashscreen_png.c := \
diff --git a/src/java.desktop/share/legal/libpng.md b/src/java.desktop/share/legal/libpng.md
index d43ccf2e8e4..8899491c6c0 100644
--- a/src/java.desktop/share/legal/libpng.md
+++ b/src/java.desktop/share/legal/libpng.md
@@ -1,4 +1,4 @@
-## libpng v1.6.47
+## libpng v1.6.51
 
 ### libpng License
 <pre>
@@ -9,7 +9,7 @@ COPYRIGHT NOTICE, DISCLAIMER, and LICENSE
 PNG Reference Library License version 2
 ---------------------------------------
 
-Copyright (c) 1995-2025 The PNG Reference Library Authors.
+Copyright (C) 1995-2025 The PNG Reference Library Authors.
 Copyright (C) 2018-2025 Cosmin Truta
 Copyright (C) 1998-2018 Glenn Randers-Pehrson
 Copyright (C) 1996-1997 Andreas Dilger
@@ -173,6 +173,7 @@ Authors, for copyright and licensing purposes.
  * Lucas Chollet
  * Magnus Holmgren
  * Mandar Sahastrabuddhe
+ * Manfred Schlaegl
  * Mans Rullgard
  * Matt Sarett
  * Mike Klein
@@ -184,6 +185,7 @@ Authors, for copyright and licensing purposes.
  * Samuel Williams
  * Simon-Pierre Cadieux
  * Tim Wegner
+ * Tobias Stoeckmann
  * Tom Lane
  * Tom Tanner
  * Vadim Barkov
@@ -193,8 +195,9 @@ Authors, for copyright and licensing purposes.
     - Zixu Wang (王子旭)
  * Arm Holdings
     - Richard Townsend
- * Google Inc.
+ * Google LLC
     - Dan Field
+    - Dragoș Tiselice
     - Leon Scroggins III
     - Matt Sarett
     - Mike Klein
@@ -204,6 +207,8 @@ Authors, for copyright and licensing purposes.
     - GuXiWei (顾希伟)
     - JinBo (金波)
     - ZhangLixia (张利霞)
+ * Samsung Group
+    - Filip Wasil
 
 The build projects, the build scripts, the test scripts, and other
 files in the "projects", "scripts" and "tests" directories, have
@@ -214,3 +219,4 @@ of the tools-generated files that are distributed with libpng, have
 other copyright owners, and are released under other open source
 licenses.
 ```
+
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/CHANGES b/src/java.desktop/share/native/libsplashscreen/libpng/CHANGES
index 834b5e19277..2478fd0fc08 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/CHANGES
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/CHANGES
@@ -6251,6 +6251,59 @@ Version 1.6.47 [February 18, 2025]
     colorspace precedence rules, due to pre-existing colorspace checks.
     (Reported by Bob Friesenhahn; fixed by John Bowler)
 
+Version 1.6.48 [April 30, 2025]
+  Fixed the floating-point version of the mDCv setter `png_set_mDCv`.
+    (Reported by Mohit Bakshi; fixed by John Bowler)
+  Added #error directives to discourage the inclusion of private
+    libpng implementation header files in PNG-supporting applications.
+  Added the CMake build option `PNG_LIBCONF_HEADER`, to be used as an
+    alternative to `DFA_XTRA`.
+  Removed the Travis CI configuration files, with heartfelt thanks for
+    their generous support of our project over the past five years!
+
+Version 1.6.49 [June 12, 2025]
+  Added SIMD-optimized code for the RISC-V Vector Extension (RVV).
+    (Contributed by Manfred Schlaegl, Dragos Tiselice and Filip Wasil)
+  Added various fixes and improvements to the build scripts and to
+    the sample code.
+
+Version 1.6.50 [July 1, 2025]
+  Improved the detection of the RVV Extension on the RISC-V platform.
+    (Contributed by Filip Wasil)
+  Replaced inline ASM with C intrinsics in the RVV code.
+    (Contributed by Filip Wasil)
+  Fixed a decoder defect in which unknown chunks trailing IDAT, set
+    to go through the unknown chunk handler, incorrectly triggered
+    out-of-place IEND errors.
+    (Contributed by John Bowler)
+  Fixed the CMake file for cross-platform builds that require `libm`.
+
+Version 1.6.51 [November 21, 2025]
+  Fixed CVE-2025-64505 (moderate severity):
+    Heap buffer overflow in `png_do_quantize` via malformed palette index.
+    (Reported by Samsung; analyzed by Fabio Gritti.)
+  Fixed CVE-2025-64506 (moderate severity):
+    Heap buffer over-read in `png_write_image_8bit` with 8-bit input and
+    `convert_to_8bit` enabled.
+    (Reported by Samsung and <weijinjinnihao@users.noreply.github.com>;
+    analyzed by Fabio Gritti.)
+  Fixed CVE-2025-64720 (high severity):
+    Buffer overflow in `png_image_read_composite` via incorrect palette
+    premultiplication.
+    (Reported by Samsung; analyzed by John Bowler.)
+  Fixed CVE-2025-65018 (high severity):
+    Heap buffer overflow in `png_combine_row` triggered via
+    `png_image_finish_read`.
+    (Reported by <yosiimich@users.noreply.github.com>.)
+  Fixed a memory leak in `png_set_quantize`.
+    (Reported by Samsung; analyzed by Fabio Gritti.)
+  Removed the experimental and incomplete ERROR_NUMBERS code.
+    (Contributed by Tobias Stoeckmann.)
+  Improved the RISC-V vector extension support; required RVV 1.0 or newer.
+    (Contributed by Filip Wasil.)
+  Added GitHub Actions workflows for automated testing.
+  Performed various refactorings and cleanups.
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net.
 Subscription is required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/README b/src/java.desktop/share/native/libsplashscreen/libpng/README
index 57952fb215a..5ea329ee3da 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/README
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/README
@@ -1,4 +1,4 @@
-README for libpng version 1.6.47
+README for libpng version 1.6.51
 ================================
 
 See the note about version numbers near the top of `png.h`.
@@ -147,6 +147,7 @@ Files included in this distribution
     loongarch/    =>  Optimized code for LoongArch LSX
     mips/         =>  Optimized code for MIPS MSA and MIPS MMI
     powerpc/      =>  Optimized code for PowerPC VSX
+    riscv/        =>  Optimized code for the RISC-V platform
     ci/           =>  Scripts for continuous integration
     contrib/      =>  External contributions
         arm-neon/     =>  Optimized code for the ARM-NEON platform
@@ -162,6 +163,7 @@ Files included in this distribution
                           programs demonstrating the use of pngusr.dfa
         pngminus/     =>  Simple pnm2png and png2pnm programs
         pngsuite/     =>  Test images
+        riscv-rvv/    =>  Optimized code for the RISC-V Vector platform
         testpngs/     =>  Test images
         tools/        =>  Various tools
         visupng/      =>  VisualPng, a Windows viewer for PNG images
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/png.c b/src/java.desktop/share/native/libsplashscreen/libpng/png.c
index 7b6de2f8ec3..7d85e7c8d5f 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/png.c
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/png.c
@@ -42,7 +42,7 @@
 #include "pngpriv.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_47 Your_png_h_is_not_version_1_6_47;
+typedef png_libpng_version_1_6_51 Your_png_h_is_not_version_1_6_51;
 
 /* Sanity check the chunks definitions - PNG_KNOWN_CHUNKS from pngpriv.h and the
  * corresponding macro definitions.  This causes a compile time failure if
@@ -137,10 +137,16 @@ png_zalloc,(voidpf png_ptr, uInt items, uInt size),PNG_ALLOCATED)
    if (png_ptr == NULL)
       return NULL;
 
-   if (items >= (~(png_alloc_size_t)0)/size)
+   /* This check against overflow is vestigial, dating back from
+    * the old times when png_zalloc used to be an exported function.
+    * We're still keeping it here for now, as an extra-cautious
+    * prevention against programming errors inside zlib, although it
+    * should rather be a debug-time assertion instead.
+    */
+   if (size != 0 && items >= (~(png_alloc_size_t)0) / size)
    {
-      png_warning (png_voidcast(png_structrp, png_ptr),
-          "Potential overflow in png_zalloc()");
+      png_warning(png_voidcast(png_structrp, png_ptr),
+                  "Potential overflow in png_zalloc()");
       return NULL;
    }
 
@@ -267,10 +273,6 @@ png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver)
       png_warning(png_ptr, m);
 #endif
 
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-      png_ptr->flags = 0;
-#endif
-
       return 0;
    }
 
@@ -729,7 +731,7 @@ png_get_io_ptr(png_const_structrp png_ptr)
  * function of your own because "FILE *" isn't necessarily available.
  */
 void PNGAPI
-png_init_io(png_structrp png_ptr, png_FILE_p fp)
+png_init_io(png_structrp png_ptr, FILE *fp)
 {
    png_debug(1, "in png_init_io");
 
@@ -844,7 +846,7 @@ png_get_copyright(png_const_structrp png_ptr)
    return PNG_STRING_COPYRIGHT
 #else
    return PNG_STRING_NEWLINE \
-      "libpng version 1.6.47" PNG_STRING_NEWLINE \
+      "libpng version 1.6.51" PNG_STRING_NEWLINE \
       "Copyright (c) 2018-2025 Cosmin Truta" PNG_STRING_NEWLINE \
       "Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson" \
       PNG_STRING_NEWLINE \
@@ -1520,7 +1522,7 @@ png_XYZ_from_xy(png_XYZ *XYZ, const png_xy *xy)
 }
 #endif /* COLORSPACE */
 
-#ifdef PNG_iCCP_SUPPORTED
+#ifdef PNG_READ_iCCP_SUPPORTED
 /* Error message generation */
 static char
 png_icc_tag_char(png_uint_32 byte)
@@ -1596,9 +1598,7 @@ png_icc_profile_error(png_const_structrp png_ptr, png_const_charp name,
 
    return 0;
 }
-#endif /* iCCP */
 
-#ifdef PNG_READ_iCCP_SUPPORTED
 /* Encoded value of D50 as an ICC XYZNumber.  From the ICC 2010 spec the value
  * is XYZ(0.9642,1.0,0.8249), which scales to:
  *
@@ -3998,7 +3998,7 @@ png_image_free_function(png_voidp argument)
 #  ifdef PNG_STDIO_SUPPORTED
       if (cp->owned_file != 0)
       {
-         FILE *fp = png_voidcast(FILE*, cp->png_ptr->io_ptr);
+         FILE *fp = png_voidcast(FILE *, cp->png_ptr->io_ptr);
          cp->owned_file = 0;
 
          /* Ignore errors here. */
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/png.h b/src/java.desktop/share/native/libsplashscreen/libpng/png.h
index ede12c34fe6..d39ff73552c 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/png.h
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/png.h
@@ -29,7 +29,7 @@
  * However, the following notice accompanied the original version of this
  * file and, per its terms, should not be removed:
  *
- * libpng version 1.6.47
+ * libpng version 1.6.51
  *
  * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
@@ -43,7 +43,7 @@
  *   libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
  *   libpng versions 0.97, January 1998, through 1.6.35, July 2018:
  *     Glenn Randers-Pehrson
- *   libpng versions 1.6.36, December 2018, through 1.6.47, February 2025:
+ *   libpng versions 1.6.36, December 2018, through 1.6.51, November 2025:
  *     Cosmin Truta
  *   See also "Contributing Authors", below.
  */
@@ -267,7 +267,7 @@
  *    ...
  *    1.5.30                  15    10530  15.so.15.30[.0]
  *    ...
- *    1.6.47                  16    10647  16.so.16.47[.0]
+ *    1.6.51                  16    10651  16.so.16.51[.0]
  *
  *    Henceforth the source version will match the shared-library major and
  *    minor numbers; the shared-library major version number will be used for
@@ -303,7 +303,7 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.47"
+#define PNG_LIBPNG_VER_STRING "1.6.51"
 #define PNG_HEADER_VERSION_STRING " libpng version " PNG_LIBPNG_VER_STRING "\n"
 
 /* The versions of shared library builds should stay in sync, going forward */
@@ -314,7 +314,7 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   6
-#define PNG_LIBPNG_VER_RELEASE 47
+#define PNG_LIBPNG_VER_RELEASE 51
 
 /* This should be zero for a public release, or non-zero for a
  * development version.
@@ -345,7 +345,7 @@
  * From version 1.0.1 it is:
  * XXYYZZ, where XX=major, YY=minor, ZZ=release
  */
-#define PNG_LIBPNG_VER 10647 /* 1.6.47 */
+#define PNG_LIBPNG_VER 10651 /* 1.6.51 */
 
 /* Library configuration: these options cannot be changed after
  * the library has been built.
@@ -455,7 +455,7 @@ extern "C" {
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef char* png_libpng_version_1_6_47;
+typedef char* png_libpng_version_1_6_51;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *
@@ -1599,7 +1599,7 @@ PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
 
 #ifdef PNG_STDIO_SUPPORTED
 /* Initialize the input/output for the PNG file to the default functions. */
-PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
+PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, FILE *fp));
 #endif
 
 /* Replace the (error and abort), and warning functions with user
@@ -3117,7 +3117,7 @@ PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
     */
 
 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
-   FILE* file));
+   FILE *file));
    /* The PNG header is read from the stdio FILE object. */
 #endif /* STDIO */
 
@@ -3192,7 +3192,7 @@ PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
    int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
    const void *colormap));
-   /* Write the image to the given (FILE*). */
+   /* Write the image to the given FILE object. */
 #endif /* SIMPLIFIED_WRITE_STDIO */
 
 /* With all write APIs if image is in one of the linear formats with 16-bit
@@ -3332,26 +3332,45 @@ PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
  *           selected at run time.
  */
 #ifdef PNG_SET_OPTION_SUPPORTED
+
+/* HARDWARE: ARM Neon SIMD instructions supported */
 #ifdef PNG_ARM_NEON_API_SUPPORTED
-#  define PNG_ARM_NEON   0 /* HARDWARE: ARM Neon SIMD instructions supported */
+#  define PNG_ARM_NEON 0
 #endif
-#define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
-#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
+
+/* SOFTWARE: Force maximum window */
+#define PNG_MAXIMUM_INFLATE_WINDOW 2
+
+/* SOFTWARE: Check ICC profile for sRGB */
+#define PNG_SKIP_sRGB_CHECK_PROFILE 4
+
+/* HARDWARE: MIPS MSA SIMD instructions supported */
 #ifdef PNG_MIPS_MSA_API_SUPPORTED
-#  define PNG_MIPS_MSA   6 /* HARDWARE: MIPS Msa SIMD instructions supported */
+#  define PNG_MIPS_MSA 6
 #endif
+
+/* SOFTWARE: Disable Adler32 check on IDAT */
 #ifdef PNG_DISABLE_ADLER32_CHECK_SUPPORTED
-#  define PNG_IGNORE_ADLER32 8 /* SOFTWARE: disable Adler32 check on IDAT */
+#  define PNG_IGNORE_ADLER32 8
 #endif
+
+/* HARDWARE: PowerPC VSX SIMD instructions supported */
 #ifdef PNG_POWERPC_VSX_API_SUPPORTED
-#  define PNG_POWERPC_VSX   10 /* HARDWARE: PowerPC VSX SIMD instructions
-                                * supported */
+#  define PNG_POWERPC_VSX 10
 #endif
+
+/* HARDWARE: MIPS MMI SIMD instructions supported */
 #ifdef PNG_MIPS_MMI_API_SUPPORTED
-#  define PNG_MIPS_MMI   12 /* HARDWARE: MIPS MMI SIMD instructions supported */
+#  define PNG_MIPS_MMI 12
+#endif
+
+/* HARDWARE: RISC-V RVV SIMD instructions supported */
+#ifdef PNG_RISCV_RVV_API_SUPPORTED
+#  define PNG_RISCV_RVV 14
 #endif
 
-#define PNG_OPTION_NEXT  14 /* Next option - numbers must be even */
+/* Next option - numbers must be even */
+#define PNG_OPTION_NEXT 16
 
 /* Return values: NOTE: there are four values and 'off' is *not* zero */
 #define PNG_OPTION_UNSET   0 /* Unset - defaults to off */
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pngconf.h b/src/java.desktop/share/native/libsplashscreen/libpng/pngconf.h
index 70bca6fa1c9..4bc5f7bb468 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pngconf.h
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pngconf.h
@@ -29,7 +29,7 @@
  * However, the following notice accompanied the original version of this
  * file and, per its terms, should not be removed:
  *
- * libpng version 1.6.47
+ * libpng version 1.6.51
  *
  * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson
@@ -248,25 +248,13 @@
   /* NOTE: PNGCBAPI always defaults to PNGCAPI. */
 
 #  if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD)
-#     error "PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed"
+#     error PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed
 #  endif
 
-#  if (defined(_MSC_VER) && _MSC_VER < 800) ||\
-      (defined(__BORLANDC__) && __BORLANDC__ < 0x500)
-   /* older Borland and MSC
-    * compilers used '__export' and required this to be after
-    * the type.
-    */
-#    ifndef PNG_EXPORT_TYPE
-#      define PNG_EXPORT_TYPE(type) type PNG_IMPEXP
-#    endif
-#    define PNG_DLL_EXPORT __export
-#  else /* newer compiler */
-#    define PNG_DLL_EXPORT __declspec(dllexport)
-#    ifndef PNG_DLL_IMPORT
-#      define PNG_DLL_IMPORT __declspec(dllimport)
-#    endif
-#  endif /* compiler */
+#  define PNG_DLL_EXPORT __declspec(dllexport)
+#  ifndef PNG_DLL_IMPORT
+#    define PNG_DLL_IMPORT __declspec(dllimport)
+#  endif
 
 #else /* !Windows */
 #  if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
@@ -508,7 +496,7 @@
 #if CHAR_BIT == 8 && UCHAR_MAX == 255
    typedef unsigned char png_byte;
 #else
-#  error "libpng requires 8-bit bytes"
+#  error libpng requires 8-bit bytes
 #endif
 
 #if INT_MIN == -32768 && INT_MAX == 32767
@@ -516,7 +504,7 @@
 #elif SHRT_MIN == -32768 && SHRT_MAX == 32767
    typedef short png_int_16;
 #else
-#  error "libpng requires a signed 16-bit type"
+#  error libpng requires a signed 16-bit integer type
 #endif
 
 #if UINT_MAX == 65535
@@ -524,7 +512,7 @@
 #elif USHRT_MAX == 65535
    typedef unsigned short png_uint_16;
 #else
-#  error "libpng requires an unsigned 16-bit type"
+#  error libpng requires an unsigned 16-bit integer type
 #endif
 
 #if INT_MIN < -2147483646 && INT_MAX > 2147483646
@@ -532,7 +520,7 @@
 #elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646
    typedef long int png_int_32;
 #else
-#  error "libpng requires a signed 32-bit (or more) type"
+#  error libpng requires a signed 32-bit (or longer) integer type
 #endif
 
 #if UINT_MAX > 4294967294U
@@ -540,7 +528,7 @@
 #elif ULONG_MAX > 4294967294U
    typedef unsigned long int png_uint_32;
 #else
-#  error "libpng requires an unsigned 32-bit (or more) type"
+#  error libpng requires an unsigned 32-bit (or longer) integer type
 #endif
 
 /* Prior to 1.6.0, it was possible to disable the use of size_t and ptrdiff_t.
@@ -621,10 +609,6 @@ typedef const png_fixed_point * png_const_fixed_point_p;
 typedef size_t                * png_size_tp;
 typedef const size_t          * png_const_size_tp;
 
-#ifdef PNG_STDIO_SUPPORTED
-typedef FILE            * png_FILE_p;
-#endif
-
 #ifdef PNG_FLOATING_POINT_SUPPORTED
 typedef double       * png_doublep;
 typedef const double * png_const_doublep;
@@ -646,6 +630,15 @@ typedef double          * * png_doublepp;
 /* Pointers to pointers to pointers; i.e., pointer to array */
 typedef char            * * * png_charppp;
 
+#ifdef PNG_STDIO_SUPPORTED
+/* With PNG_STDIO_SUPPORTED it was possible to use I/O streams that were
+ * not necessarily stdio FILE streams, to allow building Windows applications
+ * before Win32 and Windows CE applications before WinCE 3.0, but that kind
+ * of support has long been discontinued.
+ */
+typedef FILE            * png_FILE_p; /* [Deprecated] */
+#endif
+
 #endif /* PNG_BUILDING_SYMBOL_TABLE */
 
 #endif /* PNGCONF_H */
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pngdebug.h b/src/java.desktop/share/native/libsplashscreen/libpng/pngdebug.h
index 8eb5400ea9a..6ea2644dfcd 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pngdebug.h
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pngdebug.h
@@ -22,14 +22,14 @@
  * questions.
  */
 
-/* pngdebug.h - Debugging macros for libpng, also used in pngtest.c
+/* pngdebug.h - internal debugging macros for libpng
  *
  * This file is available under and governed by the GNU General Public
  * License version 2 only, as published by the Free Software Foundation.
  * However, the following notice accompanied the original version of this
  * file and, per its terms, should not be removed:
  *
- * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2013 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -39,6 +39,10 @@
  * and license in png.h
  */
 
+#ifndef PNGPRIV_H
+#  error This file must not be included by applications; please include <png.h>
+#endif
+
 /* Define PNG_DEBUG at compile time for debugging information.  Higher
  * numbers for PNG_DEBUG mean more debugging information.  This has
  * only been added since version 0.95 so it is not implemented throughout
@@ -63,9 +67,6 @@
 #define PNGDEBUG_H
 /* These settings control the formatting of messages in png.c and pngerror.c */
 /* Moved to pngdebug.h at 1.5.0 */
-#  ifndef PNG_LITERAL_SHARP
-#    define PNG_LITERAL_SHARP 0x23
-#  endif
 #  ifndef PNG_LITERAL_LEFT_SQUARE_BRACKET
 #    define PNG_LITERAL_LEFT_SQUARE_BRACKET 0x5b
 #  endif
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pngerror.c b/src/java.desktop/share/native/libsplashscreen/libpng/pngerror.c
index ea0103331d3..44c86ebfef9 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pngerror.c
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pngerror.c
@@ -29,7 +29,7 @@
  * However, the following notice accompanied the original version of this
  * file and, per its terms, should not be removed:
  *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -68,46 +68,6 @@ PNG_FUNCTION(void,PNGAPI
 png_error,(png_const_structrp png_ptr, png_const_charp error_message),
     PNG_NORETURN)
 {
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-   char msg[16];
-   if (png_ptr != NULL)
-   {
-      if ((png_ptr->flags &
-         (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
-      {
-         if (*error_message == PNG_LITERAL_SHARP)
-         {
-            /* Strip "#nnnn " from beginning of error message. */
-            int offset;
-            for (offset = 1; offset<15; offset++)
-               if (error_message[offset] == ' ')
-                  break;
-
-            if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
-            {
-               int i;
-               for (i = 0; i < offset - 1; i++)
-                  msg[i] = error_message[i + 1];
-               msg[i - 1] = '\0';
-               error_message = msg;
-            }
-
-            else
-               error_message += offset;
-         }
-
-         else
-         {
-            if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
-            {
-               msg[0] = '0';
-               msg[1] = '\0';
-               error_message = msg;
-            }
-         }
-      }
-   }
-#endif
    if (png_ptr != NULL && png_ptr->error_fn != NULL)
       (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
           error_message);
@@ -245,21 +205,6 @@ void PNGAPI
 png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
 {
    int offset = 0;
-   if (png_ptr != NULL)
-   {
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-   if ((png_ptr->flags &
-       (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
-#endif
-      {
-         if (*warning_message == PNG_LITERAL_SHARP)
-         {
-            for (offset = 1; offset < 15; offset++)
-               if (warning_message[offset] == ' ')
-                  break;
-         }
-      }
-   }
    if (png_ptr != NULL && png_ptr->warning_fn != NULL)
       (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr),
           warning_message + offset);
@@ -741,42 +686,9 @@ png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),
     PNG_NORETURN)
 {
 #ifdef PNG_CONSOLE_IO_SUPPORTED
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-   /* Check on NULL only added in 1.5.4 */
-   if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
-   {
-      /* Strip "#nnnn " from beginning of error message. */
-      int offset;
-      char error_number[16];
-      for (offset = 0; offset<15; offset++)
-      {
-         error_number[offset] = error_message[offset + 1];
-         if (error_message[offset] == ' ')
-            break;
-      }
-
-      if ((offset > 1) && (offset < 15))
-      {
-         error_number[offset - 1] = '\0';
-         fprintf(stderr, "libpng error no. %s: %s",
-             error_number, error_message + offset + 1);
-         fprintf(stderr, PNG_STRING_NEWLINE);
-      }
-
-      else
-      {
-         fprintf(stderr, "libpng error: %s, offset=%d",
-             error_message, offset);
-         fprintf(stderr, PNG_STRING_NEWLINE);
-      }
-   }
-   else
-#endif
-   {
-      fprintf(stderr, "libpng error: %s", error_message ? error_message :
-         "undefined");
-      fprintf(stderr, PNG_STRING_NEWLINE);
-   }
+   fprintf(stderr, "libpng error: %s", error_message ? error_message :
+      "undefined");
+   fprintf(stderr, PNG_STRING_NEWLINE);
 #else
    PNG_UNUSED(error_message) /* Make compiler happy */
 #endif
@@ -814,40 +726,8 @@ static void /* PRIVATE */
 png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
 {
 #ifdef PNG_CONSOLE_IO_SUPPORTED
-#  ifdef PNG_ERROR_NUMBERS_SUPPORTED
-   if (*warning_message == PNG_LITERAL_SHARP)
-   {
-      int offset;
-      char warning_number[16];
-      for (offset = 0; offset < 15; offset++)
-      {
-         warning_number[offset] = warning_message[offset + 1];
-         if (warning_message[offset] == ' ')
-            break;
-      }
-
-      if ((offset > 1) && (offset < 15))
-      {
-         warning_number[offset + 1] = '\0';
-         fprintf(stderr, "libpng warning no. %s: %s",
-             warning_number, warning_message + offset);
-         fprintf(stderr, PNG_STRING_NEWLINE);
-      }
-
-      else
-      {
-         fprintf(stderr, "libpng warning: %s",
-             warning_message);
-         fprintf(stderr, PNG_STRING_NEWLINE);
-      }
-   }
-   else
-#  endif
-
-   {
-      fprintf(stderr, "libpng warning: %s", warning_message);
-      fprintf(stderr, PNG_STRING_NEWLINE);
-   }
+   fprintf(stderr, "libpng warning: %s", warning_message);
+   fprintf(stderr, PNG_STRING_NEWLINE);
 #else
    PNG_UNUSED(warning_message) /* Make compiler happy */
 #endif
@@ -895,12 +775,8 @@ png_get_error_ptr(png_const_structrp png_ptr)
 void PNGAPI
 png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
 {
-   if (png_ptr != NULL)
-   {
-      png_ptr->flags &=
-         ((~(PNG_FLAG_STRIP_ERROR_NUMBERS |
-         PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
-   }
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(strip_mode)
 }
 #endif
 
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pngget.c b/src/java.desktop/share/native/libsplashscreen/libpng/pngget.c
index d67adbae247..ed2e7f886f5 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pngget.c
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pngget.c
@@ -29,7 +29,7 @@
  * However, the following notice accompanied the original version of this
  * file and, per its terms, should not be removed:
  *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pnginfo.h b/src/java.desktop/share/native/libsplashscreen/libpng/pnginfo.h
index bc6ed3d09c9..c79c6cc780f 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pnginfo.h
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pnginfo.h
@@ -22,14 +22,14 @@
  * questions.
  */
 
-/* pnginfo.h - header file for PNG reference library
+/* pnginfo.h - internal structures for libpng
  *
  * This file is available under and governed by the GNU General Public
  * License version 2 only, as published by the Free Software Foundation.
  * However, the following notice accompanied the original version of this
  * file and, per its terms, should not be removed:
  *
- * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2013,2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -39,43 +39,20 @@
  * and license in png.h
  */
 
- /* png_info is a structure that holds the information in a PNG file so
- * that the application can find out the characteristics of the image.
- * If you are reading the file, this structure will tell you what is
- * in the PNG file.  If you are writing the file, fill in the information
- * you want to put into the PNG file, using png_set_*() functions, then
- * call png_write_info().
- *
- * The names chosen should be very close to the PNG specification, so
- * consult that document for information about the meaning of each field.
- *
- * With libpng < 0.95, it was only possible to directly set and read the
- * the values in the png_info_struct, which meant that the contents and
- * order of the values had to remain fixed.  With libpng 0.95 and later,
- * however, there are now functions that abstract the contents of
- * png_info_struct from the application, so this makes it easier to use
- * libpng with dynamic libraries, and even makes it possible to use
- * libraries that don't have all of the libpng ancillary chunk-handing
- * functionality.  In libpng-1.5.0 this was moved into a separate private
- * file that is not visible to applications.
+#ifndef PNGPRIV_H
+#  error This file must not be included by applications; please include <png.h>
+#endif
+
+/* INTERNAL, PRIVATE definition of a PNG.
  *
- * The following members may have allocated storage attached that should be
- * cleaned up before the structure is discarded: palette, trans, text,
- * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
- * splt_palettes, scal_unit, row_pointers, and unknowns.   By default, these
- * are automatically freed when the info structure is deallocated, if they were
- * allocated internally by libpng.  This behavior can be changed by means
- * of the png_data_freer() function.
+ * png_info is a modifiable description of a PNG datastream.  The fields inside
+ * this structure are accessed through png_get_<CHUNK>() functions and modified
+ * using png_set_<CHUNK>() functions.
  *
- * More allocation details: all the chunk-reading functions that
- * change these members go through the corresponding png_set_*
- * functions.  A function to clear these members is available: see
- * png_free_data().  The png_set_* functions do not depend on being
- * able to point info structure members to any of the storage they are
- * passed (they make their own copies), EXCEPT that the png_set_text
- * functions use the same storage passed to them in the text_ptr or
- * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
- * functions do not make their own copies.
+ * Some functions in libpng do directly access members of png_info.  However,
+ * this should be avoided.  png_struct objects contain members which hold
+ * caches, sometimes optimised, of the values from png_info objects, and
+ * png_info is not passed to the functions which read and write image data.
  */
 #ifndef PNGINFO_H
 #define PNGINFO_H
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pnglibconf.h b/src/java.desktop/share/native/libsplashscreen/libpng/pnglibconf.h
index 906f855db0e..4cfae474751 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pnglibconf.h
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pnglibconf.h
@@ -31,7 +31,7 @@
  * However, the following notice accompanied the original version of this
  * file and, per its terms, should not be removed:
  */
-/* libpng version 1.6.47 */
+/* libpng version 1.6.51 */
 
 /* Copyright (c) 2018-2025 Cosmin Truta */
 /* Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson */
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pngmem.c b/src/java.desktop/share/native/libsplashscreen/libpng/pngmem.c
index ba9eb4df402..12b71bcbc02 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pngmem.c
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pngmem.c
@@ -29,7 +29,7 @@
  * However, the following notice accompanied the original version of this
  * file and, per its terms, should not be removed:
  *
- * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2014,2016 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pngpread.c b/src/java.desktop/share/native/libsplashscreen/libpng/pngpread.c
index 86d0c7aaa64..3bfa913000f 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pngpread.c
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pngpread.c
@@ -29,7 +29,7 @@
  * However, the following notice accompanied the original version of this
  * file and, per its terms, should not be removed:
  *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -258,6 +258,14 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
          png_benign_error(png_ptr, "Too many IDATs found");
    }
 
+   else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+   {
+      /* These flags must be set consistently for all non-IDAT chunks,
+       * including the unknown chunks.
+       */
+      png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT | PNG_AFTER_IDAT;
+   }
+
    if (chunk_name == png_IHDR)
    {
       if (png_ptr->push_length != 13)
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pngpriv.h b/src/java.desktop/share/native/libsplashscreen/libpng/pngpriv.h
index 25bac4b9e69..dcd005efb34 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pngpriv.h
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pngpriv.h
@@ -29,7 +29,7 @@
  * However, the following notice accompanied the original version of this
  * file and, per its terms, should not be removed:
  *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -48,8 +48,20 @@
  * they should be well aware of the issues that may arise from doing so.
  */
 
+
+/* pngpriv.h must be included first in each translation unit inside libpng.
+ * On the other hand, it must not be included at all, directly or indirectly,
+ * by any application code that uses the libpng API.
+ */
 #ifndef PNGPRIV_H
-#define PNGPRIV_H
+#  define PNGPRIV_H
+#else
+#  error Duplicate inclusion of pngpriv.h; please check the libpng source files
+#endif
+
+#if defined(PNG_H) || defined(PNGCONF_H) || defined(PNGLCONF_H)
+#  error This file must not be included by applications; please include <png.h>
+#endif
 
 /* Feature Test Macros.  The following are defined here to ensure that correctly
  * implemented libraries reveal the APIs libpng needs to build and hide those
@@ -86,7 +98,6 @@
  */
 #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
 #  include <config.h>
-
    /* Pick up the definition of 'restrict' from config.h if it was read: */
 #  define PNG_RESTRICT restrict
 #endif
@@ -96,9 +107,7 @@
  * are not internal definitions may be required.  This is handled below just
  * before png.h is included, but load the configuration now if it is available.
  */
-#ifndef PNGLCONF_H
-#  include "pnglibconf.h"
-#endif
+#include "pnglibconf.h"
 
 /* Local renames may change non-exported API functions from png.h */
 #if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
@@ -163,6 +172,20 @@
 #  endif
 #endif
 
+#ifndef PNG_RISCV_RVV_OPT
+   /* RISCV_RVV optimizations are being controlled by the compiler settings,
+    * typically the target compiler will define __riscv but the rvv extension
+    * availability has to be explicitly stated. This is why if no
+    * PNG_RISCV_RVV_OPT was defined then a runtime check will be executed.
+    *
+    * To enable RISCV_RVV optimizations unconditionally, and compile the
+    * associated code, pass --enable-riscv-rvv=yes or --enable-riscv-rvv=on
+    * to configure or put -DPNG_RISCV_RVV_OPT=2 in CPPFLAGS.
+    */
+
+#  define PNG_RISCV_RVV_OPT 0
+#endif
+
 #if PNG_ARM_NEON_OPT > 0
    /* NEON optimizations are to be at least considered by libpng, so enable the
     * callbacks to do this.
@@ -308,6 +331,16 @@
 #   define PNG_LOONGARCH_LSX_IMPLEMENTATION 0
 #endif
 
+#if PNG_RISCV_RVV_OPT > 0 && __riscv_v >= 1000000
+#  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_rvv
+#  ifndef PNG_RISCV_RVV_IMPLEMENTATION
+      /* Use the intrinsics code by default. */
+#     define PNG_RISCV_RVV_IMPLEMENTATION 1
+#  endif
+#else
+#  define PNG_RISCV_RVV_IMPLEMENTATION 0
+#endif /* PNG_RISCV_RVV_OPT > 0 && __riscv_v >= 1000000 */
+
 /* Is this a build of a DLL where compilation of the object modules requires
  * different preprocessor settings to those required for a simple library?  If
  * so PNG_BUILD_DLL must be set.
@@ -706,7 +739,7 @@
 /* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000U */
 /* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS      0x10000U */
 #define PNG_FLAG_LIBRARY_MISMATCH        0x20000U
-#define PNG_FLAG_STRIP_ERROR_NUMBERS     0x40000U
+                                  /*     0x40000U    unused */
 #define PNG_FLAG_STRIP_ERROR_TEXT        0x80000U
 #define PNG_FLAG_BENIGN_ERRORS_WARN     0x100000U /* Added to libpng-1.4.0 */
 #define PNG_FLAG_APP_WARNINGS_WARN      0x200000U /* Added to libpng-1.6.0 */
@@ -1020,17 +1053,15 @@
  * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
  */
 #if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
-#  error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
-      "-I (include path) error: see the notes in pngpriv.h"
-   /* This means that when pnglibconf.h was built the copy of zlib.h that it
-    * used is not the same as the one being used here.  Because the build of
-    * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
-    * zlib version number and because this affects handling of certain broken
-    * PNG files the -I directives must match.
+#  error The include path of <zlib.h> is incorrect
+   /* When pnglibconf.h was built, the copy of zlib.h that it used was not the
+    * same as the one being used here.  Considering how libpng makes decisions
+    * to use the zlib API based on the zlib version number, the -I options must
+    * match.
     *
-    * The most likely explanation is that you passed a -I in CFLAGS. This will
-    * not work; all the preprocessor directives and in particular all the -I
-    * directives must be in CPPFLAGS.
+    * A possible cause of this mismatch is that you passed an -I option in
+    * CFLAGS, which is unlikely to work.  All the preprocessor options, and all
+    * the -I options in particular, should be in CPPFLAGS.
     */
 #endif
 
@@ -1544,6 +1575,23 @@ PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_lsx,(png_row_infop
     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
 #endif
 
+#if PNG_RISCV_RVV_IMPLEMENTATION == 1
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_rvv,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_rvv,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_rvv,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_rvv,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_rvv,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_rvv,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_rvv,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+#endif
+
 /* Choose the best filter to use and filter the row data */
 PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
     png_row_infop row_info),PNG_EMPTY);
@@ -2156,6 +2204,11 @@ PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_lsx,
     (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
 #endif
 
+#  if PNG_RISCV_RVV_IMPLEMENTATION == 1
+PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_rvv,
+   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
+#endif
+
 PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr,
    png_const_charp key, png_bytep new_key), PNG_EMPTY);
 
@@ -2191,4 +2244,3 @@ PNG_INTERNAL_FUNCTION(int,
 #endif
 
 #endif /* PNG_VERSION_INFO_ONLY */
-#endif /* PNGPRIV_H */
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pngread.c b/src/java.desktop/share/native/libsplashscreen/libpng/pngread.c
index 8a6381e1b3e..b53668a09ce 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pngread.c
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pngread.c
@@ -731,7 +731,12 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr)
       png_uint_32 chunk_name = png_ptr->chunk_name;
 
       if (chunk_name != png_IDAT)
-         png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+      {
+         /* These flags must be set consistently for all non-IDAT chunks,
+          * including the unknown chunks.
+          */
+         png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT | PNG_AFTER_IDAT;
+      }
 
       if (chunk_name == png_IEND)
          png_handle_chunk(png_ptr, info_ptr, length);
@@ -838,7 +843,8 @@ png_read_destroy(png_structrp png_ptr)
 #endif
 
 #if defined(PNG_READ_EXPAND_SUPPORTED) && \
-    defined(PNG_ARM_NEON_IMPLEMENTATION)
+    (defined(PNG_ARM_NEON_IMPLEMENTATION) || \
+     defined(PNG_RISCV_RVV_IMPLEMENTATION))
    png_free(png_ptr, png_ptr->riffled_palette);
    png_ptr->riffled_palette = NULL;
 #endif
@@ -1357,7 +1363,7 @@ png_image_read_header(png_voidp argument)
 
 #ifdef PNG_STDIO_SUPPORTED
 int PNGAPI
-png_image_begin_read_from_stdio(png_imagep image, FILE* file)
+png_image_begin_read_from_stdio(png_imagep image, FILE *file)
 {
    if (image != NULL && image->version == PNG_IMAGE_VERSION)
    {
@@ -3152,6 +3158,54 @@ png_image_read_colormapped(png_voidp argument)
    }
 }
 
+/* Row reading for interlaced 16-to-8 bit depth conversion with local buffer. */
+static int
+png_image_read_direct_scaled(png_voidp argument)
+{
+   png_image_read_control *display = png_voidcast(png_image_read_control*,
+       argument);
+   png_imagep image = display->image;
+   png_structrp png_ptr = image->opaque->png_ptr;
+   png_bytep local_row = png_voidcast(png_bytep, display->local_row);
+   png_bytep first_row = png_voidcast(png_bytep, display->first_row);
+   ptrdiff_t row_bytes = display->row_bytes;
+   int passes;
+
+   /* Handle interlacing. */
+   switch (png_ptr->interlaced)
+   {
+      case PNG_INTERLACE_NONE:
+         passes = 1;
+         break;
+
+      case PNG_INTERLACE_ADAM7:
+         passes = PNG_INTERLACE_ADAM7_PASSES;
+         break;
+
+      default:
+         png_error(png_ptr, "unknown interlace type");
+   }
+
+   /* Read each pass using local_row as intermediate buffer. */
+   while (--passes >= 0)
+   {
+      png_uint_32 y = image->height;
+      png_bytep output_row = first_row;
+
+      for (; y > 0; --y)
+      {
+         /* Read into local_row (gets transformed 8-bit data). */
+         png_read_row(png_ptr, local_row, NULL);
+
+         /* Copy from local_row to user buffer. */
+         memcpy(output_row, local_row, (size_t)row_bytes);
+         output_row += row_bytes;
+      }
+   }
+
+   return 1;
+}
+
 /* Just the row reading part of png_image_read. */
 static int
 png_image_read_composite(png_voidp argument)
@@ -3570,6 +3624,7 @@ png_image_read_direct(png_voidp argument)
    int linear = (format & PNG_FORMAT_FLAG_LINEAR) != 0;
    int do_local_compose = 0;
    int do_local_background = 0; /* to avoid double gamma correction bug */
+   int do_local_scale = 0; /* for interlaced 16-to-8 bit conversion */
    int passes = 0;
 
    /* Add transforms to ensure the correct output format is produced then check
@@ -3703,8 +3758,16 @@ png_image_read_direct(png_voidp argument)
             png_set_expand_16(png_ptr);
 
          else /* 8-bit output */
+         {
             png_set_scale_16(png_ptr);
 
+            /* For interlaced images, use local_row buffer to avoid overflow
+             * in png_combine_row() which writes using IHDR bit-depth.
+             */
+            if (png_ptr->interlaced != 0)
+               do_local_scale = 1;
+         }
+
          change &= ~PNG_FORMAT_FLAG_LINEAR;
       }
 
@@ -3980,6 +4043,24 @@ png_image_read_direct(png_voidp argument)
       return result;
    }
 
+   else if (do_local_scale != 0)
+   {
+      /* For interlaced 16-to-8 conversion, use an intermediate row buffer
+       * to avoid buffer overflows in png_combine_row. The local_row is sized
+       * for the transformed (8-bit) output, preventing the overflow that would
+       * occur if png_combine_row wrote 16-bit data directly to the user buffer.
+       */
+      int result;
+      png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
+
+      display->local_row = row;
+      result = png_safe_execute(image, png_image_read_direct_scaled, display);
+      display->local_row = NULL;
+      png_free(png_ptr, row);
+
+      return result;
+   }
+
    else
    {
       png_alloc_size_t row_bytes = (png_alloc_size_t)display->row_bytes;
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pngrio.c b/src/java.desktop/share/native/libsplashscreen/libpng/pngrio.c
index 961d010df42..50a424d0912 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pngrio.c
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pngrio.c
@@ -29,7 +29,7 @@
  * However, the following notice accompanied the original version of this
  * file and, per its terms, should not be removed:
  *
- * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -85,7 +85,7 @@ png_default_read_data(png_structp png_ptr, png_bytep data, size_t length)
    /* fread() returns 0 on error, so it is OK to store this in a size_t
     * instead of an int, which is what fread() actually returns.
     */
-   check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr));
+   check = fread(data, 1, length, png_voidcast(FILE *, png_ptr->io_ptr));
 
    if (check != length)
       png_error(png_ptr, "Read Error");
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pngrtran.c b/src/java.desktop/share/native/libsplashscreen/libpng/pngrtran.c
index 4f31f8f07bc..a19615f49fe 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pngrtran.c
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pngrtran.c
@@ -29,7 +29,7 @@
  * However, the following notice accompanied the original version of this
  * file and, per its terms, should not be removed:
  *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -57,6 +57,12 @@
 #  endif
 #endif
 
+#ifdef PNG_RISCV_RVV_IMPLEMENTATION
+#  if PNG_RISCV_RVV_IMPLEMENTATION == 1
+#    define PNG_RISCV_RVV_INTRINSICS_AVAILABLE
+#  endif
+#endif
+
 #ifdef PNG_READ_SUPPORTED
 
 /* Set the action on getting a CRC error for an ancillary or critical chunk. */
@@ -524,9 +530,19 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
    {
       int i;
 
+      /* Initialize the array to index colors.
+       *
+       * Ensure quantize_index can fit 256 elements (PNG_MAX_PALETTE_LENGTH)
+       * rather than num_palette elements. This is to prevent buffer overflows
+       * caused by malformed PNG files with out-of-range palette indices.
+       *
+       * Be careful to avoid leaking memory. Applications are allowed to call
+       * this function more than once per png_struct.
+       */
+      png_free(png_ptr, png_ptr->quantize_index);
       png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr,
-          (png_alloc_size_t)num_palette);
-      for (i = 0; i < num_palette; i++)
+          PNG_MAX_PALETTE_LENGTH);
+      for (i = 0; i < PNG_MAX_PALETTE_LENGTH; i++)
          png_ptr->quantize_index[i] = (png_byte)i;
    }
 
@@ -538,15 +554,14 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
           * Perhaps not the best solution, but good enough.
           */
 
-         int i;
+         png_bytep quantize_sort;
+         int i, j;
 
-         /* Initialize an array to sort colors */
-         png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr,
+         /* Initialize the local array to sort colors. */
+         quantize_sort = (png_bytep)png_malloc(png_ptr,
              (png_alloc_size_t)num_palette);
-
-         /* Initialize the quantize_sort array */
          for (i = 0; i < num_palette; i++)
-            png_ptr->quantize_sort[i] = (png_byte)i;
+            quantize_sort[i] = (png_byte)i;
 
          /* Find the least used palette entries by starting a
           * bubble sort, and running it until we have sorted
@@ -558,19 +573,18 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
          for (i = num_palette - 1; i >= maximum_colors; i--)
          {
             int done; /* To stop early if the list is pre-sorted */
-            int j;
 
             done = 1;
             for (j = 0; j < i; j++)
             {
-               if (histogram[png_ptr->quantize_sort[j]]
-                   < histogram[png_ptr->quantize_sort[j + 1]])
+               if (histogram[quantize_sort[j]]
+                   < histogram[quantize_sort[j + 1]])
                {
                   png_byte t;
 
-                  t = png_ptr->quantize_sort[j];
-                  png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1];
-                  png_ptr->quantize_sort[j + 1] = t;
+                  t = quantize_sort[j];
+                  quantize_sort[j] = quantize_sort[j + 1];
+                  quantize_sort[j + 1] = t;
                   done = 0;
                }
             }
@@ -582,18 +596,18 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
          /* Swap the palette around, and set up a table, if necessary */
          if (full_quantize != 0)
          {
-            int j = num_palette;
+            j = num_palette;
 
             /* Put all the useful colors within the max, but don't
              * move the others.
              */
             for (i = 0; i < maximum_colors; i++)
             {
-               if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
+               if ((int)quantize_sort[i] >= maximum_colors)
                {
                   do
                      j--;
-                  while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
+                  while ((int)quantize_sort[j] >= maximum_colors);
 
                   palette[i] = palette[j];
                }
@@ -601,7 +615,7 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
          }
          else
          {
-            int j = num_palette;
+            j = num_palette;
 
             /* Move all the used colors inside the max limit, and
              * develop a translation table.
@@ -609,13 +623,13 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
             for (i = 0; i < maximum_colors; i++)
             {
                /* Only move the colors we need to */
-               if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
+               if ((int)quantize_sort[i] >= maximum_colors)
                {
                   png_color tmp_color;
 
                   do
                      j--;
-                  while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
+                  while ((int)quantize_sort[j] >= maximum_colors);
 
                   tmp_color = palette[j];
                   palette[j] = palette[i];
@@ -653,8 +667,7 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
                }
             }
          }
-         png_free(png_ptr, png_ptr->quantize_sort);
-         png_ptr->quantize_sort = NULL;
+         png_free(png_ptr, quantize_sort);
       }
       else
       {
@@ -1797,19 +1810,51 @@ png_init_read_transformations(png_structrp png_ptr)
                   }
                   else /* if (png_ptr->trans_alpha[i] != 0xff) */
                   {
-                     png_byte v, w;
-
-                     v = png_ptr->gamma_to_1[palette[i].red];
-                     png_composite(w, v, png_ptr->trans_alpha[i], back_1.red);
-                     palette[i].red = png_ptr->gamma_from_1[w];
-
-                     v = png_ptr->gamma_to_1[palette[i].green];
-                     png_composite(w, v, png_ptr->trans_alpha[i], back_1.green);
-                     palette[i].green = png_ptr->gamma_from_1[w];
-
-                     v = png_ptr->gamma_to_1[palette[i].blue];
-                     png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue);
-                     palette[i].blue = png_ptr->gamma_from_1[w];
+                     if ((png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0)
+                     {
+                        /* Premultiply only:
+                         * component = round((component * alpha) / 255)
+                         */
+                        png_uint_32 component;
+
+                        component = png_ptr->gamma_to_1[palette[i].red];
+                        component =
+                            (component * png_ptr->trans_alpha[i] + 128) / 255;
+                        palette[i].red = png_ptr->gamma_from_1[component];
+
+                        component = png_ptr->gamma_to_1[palette[i].green];
+                        component =
+                            (component * png_ptr->trans_alpha[i] + 128) / 255;
+                        palette[i].green = png_ptr->gamma_from_1[component];
+
+                        component = png_ptr->gamma_to_1[palette[i].blue];
+                        component =
+                            (component * png_ptr->trans_alpha[i] + 128) / 255;
+                        palette[i].blue = png_ptr->gamma_from_1[component];
+                     }
+                     else
+                     {
+                        /* Composite with background color:
+                         * component =
+                         *    alpha * component + (1 - alpha) * background
+                         */
+                        png_byte v, w;
+
+                        v = png_ptr->gamma_to_1[palette[i].red];
+                        png_composite(w, v,
+                            png_ptr->trans_alpha[i], back_1.red);
+                        palette[i].red = png_ptr->gamma_from_1[w];
+
+                        v = png_ptr->gamma_to_1[palette[i].green];
+                        png_composite(w, v,
+                            png_ptr->trans_alpha[i], back_1.green);
+                        palette[i].green = png_ptr->gamma_from_1[w];
+
+                        v = png_ptr->gamma_to_1[palette[i].blue];
+                        png_composite(w, v,
+                            png_ptr->trans_alpha[i], back_1.blue);
+                        palette[i].blue = png_ptr->gamma_from_1[w];
+                     }
                   }
                }
                else
@@ -5032,13 +5077,8 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
 
 #ifdef PNG_READ_QUANTIZE_SUPPORTED
    if ((png_ptr->transformations & PNG_QUANTIZE) != 0)
-   {
       png_do_quantize(row_info, png_ptr->row_buf + 1,
           png_ptr->palette_lookup, png_ptr->quantize_index);
-
-      if (row_info->rowbytes == 0)
-         png_error(png_ptr, "png_do_quantize returned rowbytes=0");
-   }
 #endif /* READ_QUANTIZE */
 
 #ifdef PNG_READ_EXPAND_16_SUPPORTED
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pngrutil.c b/src/java.desktop/share/native/libsplashscreen/libpng/pngrutil.c
index 6cf466d182a..07d53cb2c76 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pngrutil.c
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pngrutil.c
@@ -29,7 +29,7 @@
  * However, the following notice accompanied the original version of this
  * file and, per its terms, should not be removed:
  *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -2441,10 +2441,6 @@ png_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
    }
 #endif
 
-   /* TODO: this doesn't work and shouldn't be necessary. */
-   if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
-      png_ptr->mode |= PNG_AFTER_IDAT;
-
    buffer = png_read_buffer(png_ptr, length+1);
 
    if (buffer == NULL)
@@ -2515,10 +2511,6 @@ png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
    }
 #endif
 
-   /* TODO: should not be necessary. */
-   if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
-      png_ptr->mode |= PNG_AFTER_IDAT;
-
    /* Note, "length" is sufficient here; we won't be adding
     * a null terminator later.  The limit check in png_handle_chunk should be
     * sufficient.
@@ -2635,10 +2627,6 @@ png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
    }
 #endif
 
-   /* TODO: should not be necessary. */
-   if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
-      png_ptr->mode |= PNG_AFTER_IDAT;
-
    buffer = png_read_buffer(png_ptr, length+1);
 
    if (buffer == NULL)
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pngset.c b/src/java.desktop/share/native/libsplashscreen/libpng/pngset.c
index 1bfd292bd46..0b2844f1864 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pngset.c
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pngset.c
@@ -329,17 +329,14 @@ png_set_mDCV(png_const_structrp png_ptr, png_inforp info_ptr,
     double maxDL, double minDL)
 {
    png_set_mDCV_fixed(png_ptr, info_ptr,
-      /* The ITU approach is to scale by 50,000, not 100,000 so just divide
-       * the input values by 2 and use png_fixed:
-       */
-      png_fixed(png_ptr, white_x / 2, "png_set_mDCV(white(x))"),
-      png_fixed(png_ptr, white_y / 2, "png_set_mDCV(white(y))"),
-      png_fixed(png_ptr, red_x / 2, "png_set_mDCV(red(x))"),
-      png_fixed(png_ptr, red_y / 2, "png_set_mDCV(red(y))"),
-      png_fixed(png_ptr, green_x / 2, "png_set_mDCV(green(x))"),
-      png_fixed(png_ptr, green_y / 2, "png_set_mDCV(green(y))"),
-      png_fixed(png_ptr, blue_x / 2, "png_set_mDCV(blue(x))"),
-      png_fixed(png_ptr, blue_y / 2, "png_set_mDCV(blue(y))"),
+      png_fixed(png_ptr, white_x, "png_set_mDCV(white(x))"),
+      png_fixed(png_ptr, white_y, "png_set_mDCV(white(y))"),
+      png_fixed(png_ptr, red_x, "png_set_mDCV(red(x))"),
+      png_fixed(png_ptr, red_y, "png_set_mDCV(red(y))"),
+      png_fixed(png_ptr, green_x, "png_set_mDCV(green(x))"),
+      png_fixed(png_ptr, green_y, "png_set_mDCV(green(y))"),
+      png_fixed(png_ptr, blue_x, "png_set_mDCV(blue(x))"),
+      png_fixed(png_ptr, blue_y, "png_set_mDCV(blue(y))"),
       png_fixed_ITU(png_ptr, maxDL, "png_set_mDCV(maxDL)"),
       png_fixed_ITU(png_ptr, minDL, "png_set_mDCV(minDL)"));
 }
diff --git a/src/java.desktop/share/native/libsplashscreen/libpng/pngstruct.h b/src/java.desktop/share/native/libsplashscreen/libpng/pngstruct.h
index d6c446564d1..8edb4bc393a 100644
--- a/src/java.desktop/share/native/libsplashscreen/libpng/pngstruct.h
+++ b/src/java.desktop/share/native/libsplashscreen/libpng/pngstruct.h
@@ -22,14 +22,14 @@
  * questions.
  */
 
-/* pngstruct.h - header file for PNG reference library
+/* pngstruct.h - internal structures for libpng
  *
  * This file is available under and governed by the GNU General Public
  * License version 2 only, as published by the Free Software Foundation.
  * However, the following notice accompanied the original version of this
  * file and, per its terms, should not be removed:
  *
- * Copyright (c) 2018-2022 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -39,11 +39,9 @@
  * and license in png.h
  */
 
-/* The structure that holds the information to read and write PNG files.
- * The only people who need to care about what is inside of this are the
- * people who will be modifying the library for their own special needs.
- * It should NOT be accessed directly by an application.
- */
+#ifndef PNGPRIV_H
+#  error This file must not be included by applications; please include <png.h>
+#endif
 
 #ifndef PNGSTRUCT_H
 #define PNGSTRUCT_H
@@ -406,7 +404,8 @@ struct png_struct_def
 
 /* New member added in libpng-1.6.36 */
 #if defined(PNG_READ_EXPAND_SUPPORTED) && \
-    defined(PNG_ARM_NEON_IMPLEMENTATION)
+    (defined(PNG_ARM_NEON_IMPLEMENTATION) || \
+     defined(PNG_RISCV_RVV_IMPLEMENTATION))
    png_bytep riffled_palette; /* buffer for accelerated palette expansion */
 #endif
 
@@ -435,7 +434,6 @@ struct png_struct_def
 
 #ifdef PNG_READ_QUANTIZE_SUPPORTED
 /* The following three members were added at version 1.0.14 and 1.2.4 */
-   png_bytep quantize_sort;          /* working sort array */
    png_bytep index_to_palette;       /* where the original index currently is
                                         in the palette */
    png_bytep palette_to_index;       /* which original index points to this