CVE-2025-64506: libpng Out-of-bounds Read — Fix

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.

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CVSS v3.1 Score

6.1

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H

Weakness Type (CWE)

CWE-125 Out-of-bounds Read

Affected Products

Vendor	Product	Versions
libpng	libpng	1.6.0 — 1.6.51

References

Advisories & Patches

https://github.com/pnggroup/libpng/commit/2bd84c019c300b78e811743fbcddb67c9d9bf821 https://github.com/pnggroup/libpng/security/advisories/GHSA-qpr4-xm66-hww6

Other References

https://github.com/pnggroup/libpng/pull/749

Frequently Asked Questions

What is CVE-2025-64506? +

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. It has a CVSS v3.1 base score of 6.1 (MEDIUM).

How severe is CVE-2025-64506? +

CVE-2025-64506 has a CVSS v3.1 score of 6.1 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-64506? +

CVE-2025-64506 affects products from libpng, specifically: libpng. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-64506? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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