From f708b0349b6076faa284134279781f7ddeacb139 Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Sun, 1 Mar 2026 10:37:26 +0100
Subject: [PATCH 1/5] Fix reference leak in listiter_reduce_general

---
 Objects/listobject.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Objects/listobject.c b/Objects/listobject.c
index 4a98c8e54ab03f..527b970af24bb2 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -4270,7 +4270,9 @@ listiter_reduce_general(void *_it, int forward)
     }
     /* empty iterator, create an empty list */
     list = PyList_New(0);
-    if (list == NULL)
+    if (list == NULL) {
+        Py_DECREF(iter);
         return NULL;
+    }
     return Py_BuildValue("N(N)", iter, list);
 }

From 551a741da5a0dfaf196dfaf51573597ac5cb095c Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Sun, 1 Mar 2026 10:39:20 +0100
Subject: [PATCH 2/5] Fix reference leak in increment_longindex_lock_held

---
 Objects/enumobject.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Objects/enumobject.c b/Objects/enumobject.c
index 814ce4f919514b..d812d83bb8156d 100644
--- a/Objects/enumobject.c
+++ b/Objects/enumobject.c
@@ -188,6 +188,7 @@ increment_longindex_lock_held(enumobject *en)
     assert(next_index != NULL);
     PyObject *stepped_up = PyNumber_Add(next_index, en->one);
     if (stepped_up == NULL) {
+        Py_DECREF(next_index);
         return NULL;
     }
     en->en_longindex = stepped_up;

From 7015ae6ccb2d290edf8e92972249bb79a91e214c Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Sun, 1 Mar 2026 11:02:49 +0100
Subject: [PATCH 3/5] fix reference leak in count_nextlong

---
 Modules/itertoolsmodule.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index ff0e2fd2b3569d..9c8dc012ad81ff 100644
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -3538,6 +3538,7 @@ count_nextlong(countobject *lz)
     if (long_cnt == NULL) {
         /* Switch to slow_mode */
         long_cnt = PyLong_FromSsize_t(PY_SSIZE_T_MAX);
+        lz->long_cnt = long_cnt;
         if (long_cnt == NULL)
             return NULL;
     }

From c02d2dbf960d020232c8c43f6d65f54bec6da003 Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Sun, 1 Mar 2026 11:08:11 +0100
Subject: [PATCH 4/5] fix reference leak in count_nextlong

---
 Modules/itertoolsmodule.c | 5 +++--
 Objects/enumobject.c      | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index 9c8dc012ad81ff..50e93c348afed5 100644
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -3538,9 +3538,10 @@ count_nextlong(countobject *lz)
     if (long_cnt == NULL) {
         /* Switch to slow_mode */
         long_cnt = PyLong_FromSsize_t(PY_SSIZE_T_MAX);
-        lz->long_cnt = long_cnt;
-        if (long_cnt == NULL)
+        if (long_cnt == NULL) {
             return NULL;
+        }
+        lz->long_cnt = long_cnt;
     }
     assert(lz->cnt == PY_SSIZE_T_MAX && long_cnt != NULL);
 
diff --git a/Objects/enumobject.c b/Objects/enumobject.c
index d812d83bb8156d..8feb074f66a0cd 100644
--- a/Objects/enumobject.c
+++ b/Objects/enumobject.c
@@ -184,11 +184,11 @@ increment_longindex_lock_held(enumobject *en)
         if (next_index == NULL) {
             return NULL;
         }
+        en->en_longindex = next_index;
     }
     assert(next_index != NULL);
     PyObject *stepped_up = PyNumber_Add(next_index, en->one);
     if (stepped_up == NULL) {
-        Py_DECREF(next_index);
         return NULL;
     }
     en->en_longindex = stepped_up;

From ff7709c256794e9b89fb43c19d3bdb2377f82101 Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Sun, 1 Mar 2026 10:15:13 +0000
Subject: [PATCH 5/5] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20blu?=
 =?UTF-8?q?rb=5Fit.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../2026-03-01-10-15-06.gh-issue-145376.lG5u1a.rst               | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2026-03-01-10-15-06.gh-issue-145376.lG5u1a.rst

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-03-01-10-15-06.gh-issue-145376.lG5u1a.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-03-01-10-15-06.gh-issue-145376.lG5u1a.rst
new file mode 100644
index 00000000000000..a5a6908757e458
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-03-01-10-15-06.gh-issue-145376.lG5u1a.rst
@@ -0,0 +1 @@
+Fix reference leaks in various unusual error scenarios.