CVE-2026-25646 HIGH

CVE-2026-25646: LIBPNG has a heap buffer overflow in png_set_quantize

Vendor Pnggroup
Product libpng
Weakness CWE-122
Published February 10, 2026
Last update June 30, 2026

CVSS base score

8.3/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Prior to 1.6.55, an out-of-bounds read vulnerability exists in the png_set_quantize() API function. When the function is called with no histogram and the number of colors in the palette is more than twice the maximum supported by the user's display, certain palettes will cause the function to enter into an infinite loop that reads past the end of an internal heap-allocated buffer. The images that trigger this vulnerability are valid per the PNG specification. This vulnerability is fixed in 1.6.55.

Key dates

02Disclosure timeline

February 10, 2026 CVE published
June 30, 2026 Record updated