# CVE-2025-64506: LIBPNG is vulnerable to a heap buffer over-read in `png_write_image_8bit` with grayscale+alpha or RGB/RGBA images CVE-2025-64506 is fixed in 15 products on 1 platform, first by libpng-tools 1.6.34-1ubuntu0.18.04.2+esm1, released November 24, 2025. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2025-64506 - Priority: Routine - CVSS: 6.1 (Moderate) - EPSS: 0.0015 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Nov 24, 2025 - Weakness: Out-of-bounds Read - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-64506 ## Description LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From version 1.6.0 to before 1.6.51, a heap buffer over-read vulnerability exists in libpng's png_write_image_8bit function when processing 8-bit images through the simplified write API with convert_to_8bit enabled. The vulnerability affects 8-bit grayscale+alpha, RGB/RGBA, and images with incomplete row data. A conditional guard incorrectly allows 8-bit input to enter code expecting 16-bit input, causing reads up to 2 bytes beyond allocated buffer boundaries. This issue has been patched in version 1.6.51. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | firefox amzn 2023 | 140.5.0-1.amzn2023.0.2 | [ALAS2023-2025-1305](https://patchblox.com/security/data/fix/linux/alas2023-2025-1305.md) | Dec 8, 2025 | | Linux | firefox-debuginfo amzn 2023 | 140.5.0-1.amzn2023.0.2 | [ALAS2023-2025-1305](https://patchblox.com/security/data/fix/linux/alas2023-2025-1305.md) | Dec 8, 2025 | | Linux | firefox-debugsource amzn 2023 | 140.5.0-1.amzn2023.0.2 | [ALAS2023-2025-1305](https://patchblox.com/security/data/fix/linux/alas2023-2025-1305.md) | Dec 8, 2025 | | Linux | libpng amzn 2023 | 2:1.6.37-10.amzn2023.0.7 | [ALAS2023-2025-1306](https://patchblox.com/security/data/fix/linux/alas2023-2025-1306.md) | Dec 8, 2025 | | Linux | libpng-debuginfo amzn 2023 | 2:1.6.37-10.amzn2023.0.7 | [ALAS2023-2025-1306](https://patchblox.com/security/data/fix/linux/alas2023-2025-1306.md) | Dec 8, 2025 | | Linux | libpng-debugsource amzn 2023 | 2:1.6.37-10.amzn2023.0.7 | [ALAS2023-2025-1306](https://patchblox.com/security/data/fix/linux/alas2023-2025-1306.md) | Dec 8, 2025 | | Linux | libpng-devel amzn 2023 | 2:1.6.37-10.amzn2023.0.7 | [ALAS2023-2025-1306](https://patchblox.com/security/data/fix/linux/alas2023-2025-1306.md) | Dec 8, 2025 | | Linux | libpng-devel-debuginfo amzn 2023 | 2:1.6.37-10.amzn2023.0.7 | [ALAS2023-2025-1306](https://patchblox.com/security/data/fix/linux/alas2023-2025-1306.md) | Dec 8, 2025 | | Linux | libpng-static amzn 2023 | 2:1.6.37-10.amzn2023.0.7 | [ALAS2023-2025-1306](https://patchblox.com/security/data/fix/linux/alas2023-2025-1306.md) | Dec 8, 2025 | | Linux | libpng-tools Ubuntu 18.04.6 LTS (bionic) | 1.6.34-1ubuntu0.18.04.2+esm1 | [libpng-tools 1.6.34-1ubuntu0.18.04.2+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libpng-tools-1.6.34-1ubuntu0.18.04.2-esm1.md) | Nov 24, 2025 | | Linux | libpng-tools Ubuntu 20.04 LTS (focal) | 1.6.37-2ubuntu0.1~esm1 | [libpng-tools 1.6.37-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libpng-tools-1.6.37-2ubuntu0.1-esm1.md) | Nov 24, 2025 | | Linux | libpng-tools Ubuntu 22.04.1 LTS (jammy) | 1.6.37-3ubuntu0.1 | [libpng-tools 1.6.37-3ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libpng-tools-1.6.37-3ubuntu0.1.md) | Nov 24, 2025 | | Linux | libpng-tools Ubuntu 24.04.5 LTS (noble) | 1.6.43-5ubuntu0.1 | [libpng-tools 1.6.43-5ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libpng-tools-1.6.43-5ubuntu0.1.md) | Nov 24, 2025 | | Linux | libpng-tools Ubuntu 25.10 (questing) | 1.6.50-1ubuntu0.1 | [libpng-tools 1.6.50-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-questing-libpng-tools-1.6.50-1ubuntu0.1.md) | Nov 24, 2025 | | Linux | libpng-tools amzn 2023 | 2:1.6.37-10.amzn2023.0.7 | [ALAS2023-2025-1306](https://patchblox.com/security/data/fix/linux/alas2023-2025-1306.md) | Dec 8, 2025 | | Linux | libpng-tools-debuginfo amzn 2023 | 2:1.6.37-10.amzn2023.0.7 | [ALAS2023-2025-1306](https://patchblox.com/security/data/fix/linux/alas2023-2025-1306.md) | Dec 8, 2025 | | Linux | libpng1.6 Debian 12.15 (bookworm) | 1.6.39-2+deb12u1 | [DEBIAN-CVE-2025-64506](https://patchblox.com/security/data/fix/linux/debian-cve-2025-64506.md) | Nov 25, 2025 | | Linux | libpng1.6 Debian 13.5 (trixie) | 1.6.48-1+deb13u1 | [DEBIAN-CVE-2025-64506](https://patchblox.com/security/data/fix/linux/debian-cve-2025-64506.md) | Nov 25, 2025 | | Linux | libpng1.6 Debian 14 | 1.6.51-1 | [DEBIAN-CVE-2025-64506](https://patchblox.com/security/data/fix/linux/debian-cve-2025-64506.md) | Nov 25, 2025 | | Linux | libpng16 opensuse-leap 15.6 | 1.6.40-150600.3.3.1 | [SUSE-SU-2025:4494-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4494-1.md) | Dec 19, 2025 | | Linux | libpng16 opensuse-leap 16.0 | 1.6.44-160000.3.1 | [OPENSUSE-SU-2026:20017-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-20017-1.md) | Jan 12, 2026 | | Linux | libpng16 sles 15.6 | 1.6.40-150600.3.3.1 | [SUSE-SU-2025:4494-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4494-1.md) | Dec 19, 2025 | | Linux | libpng16 sles 15.7 | 1.6.40-150600.3.3.1 | [SUSE-SU-2025:4494-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4494-1.md) | Dec 19, 2025 | | Linux | libpng16 sles 16.0 | 1.6.44-160000.3.1 | [SUSE-SU-2026:20030-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20030-1.md) | Jan 12, 2026 | | Linux | libpng16-16 Ubuntu 18.04.6 LTS (bionic) | 1.6.34-1ubuntu0.18.04.2+esm1 | [libpng16-16 1.6.34-1ubuntu0.18.04.2+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libpng16-16-1.6.34-1ubuntu0.18.04.2-esm1.md) | Nov 24, 2025 | | Linux | libpng16-16 Ubuntu 20.04 LTS (focal) | 1.6.37-2ubuntu0.1~esm1 | [libpng16-16 1.6.37-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libpng16-16-1.6.37-2ubuntu0.1-esm1.md) | Nov 24, 2025 | | Linux | libpng16-16 Ubuntu 22.04.1 LTS (jammy) | 1.6.37-3ubuntu0.1 | [libpng16-16 1.6.37-3ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libpng16-16-1.6.37-3ubuntu0.1.md) | Nov 24, 2025 | | Linux | libpng16-16t64 Ubuntu 24.04.5 LTS (noble) | 1.6.43-5ubuntu0.1 | [libpng16-16t64 1.6.43-5ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libpng16-16t64-1.6.43-5ubuntu0.1.md) | Nov 24, 2025 | | Linux | libpng16-16t64 Ubuntu 25.10 (questing) | 1.6.50-1ubuntu0.1 | [libpng16-16t64 1.6.50-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-questing-libpng16-16t64-1.6.50-1ubuntu0.1.md) | Nov 24, 2025 | --- Data as of 2026-11-08T19:12:23Z UTC. 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