diff --git a/.github/workflows/reusable-trivy.yml b/.github/workflows/reusable-trivy.yml
index c654c0a..3423ff4 100644
--- a/.github/workflows/reusable-trivy.yml
+++ b/.github/workflows/reusable-trivy.yml
@@ -158,6 +158,20 @@ jobs:
       actions: read
       packages: read
     steps:
+      # image-ref is a ghcr.io reference by digest (see the usage comment at
+      # the top of this file). `permissions: packages: read` alone does not
+      # authenticate the docker/trivy pull for a private package - confirmed
+      # by a real failure (unauthorized pulling a same-run-pushed private
+      # GHCR image) before this step existed. Every caller of this reusable
+      # publishes to ghcr.io, so logging in here (not conditionally, not
+      # registry-parsed from image-ref) covers every real usage.
+      - name: Log in to GHCR for the image pull
+        uses: docker/login-action@c99871dec2022cc055c062a10cc1a1310835ceb4 # v4.3.0
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
       - name: Trivy image vulnerability scan
         uses: aquasecurity/trivy-action@ed142fd0673e97e23eac54620cfb913e5ce36c25 # v0.36.0
         with: