VulnerabilityModified

CVE-2026-25646

Prior to 1.6.55, an out-of-bounds read vulnerability exists in the png_set_quantize() API function.

HIGH 8.3EPSS 1.09%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.09%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 4.0: 8.3 HIGHCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 1.09% probability · 65th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-122, CWE-126, CWE-125
Affected: libpng/libpng
Source: security-advisories@github.com

EPSS trend

EPSS 1.1% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.