CVE-2026-22801: LIBPNG has an integer truncation causing heap buffer over-read in png_image_write_*

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-01-12 · updated 2026-06-17
Weakness: CWE-125

Description

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From 1.6.26 to 1.6.53, there is an integer truncation in the libpng simplified write API functions png_write_image_16bit and png_write_image_8bit causes heap buffer over-read when the caller provides a negative row stride (for bottom-up image layouts) or a stride exceeding 65535 bytes. The bug was introduced in libpng 1.6.26 (October 2016) by casts added to silence compiler warnings on 16-bit systems. This vulnerability is fixed in 1.6.54.

Affected products

pnggroup libpng: from 1.6.26 before 1.6.54 — fixed in 1.6.54

How to fix

Upgrade to a fixed version: pnggroup libpng 1.6.54. Check the vendor advisory for mitigations.

References

https://github.com/pnggroup/libpng/security/advisories/GHSA-vgjq-8cw5-ggw8

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