Bug 2438542 (CVE-2026-25646)

Summary:	CVE-2026-25646 libpng: LIBPNG has a heap buffer overflow in png_set_quantize
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	adudiak, ahughes, caswilli, crizzo, fferrari, fitzsim, gotiwari, gtanzill, jbuscemi, jgrulich, jhorak, kaycoth, khosford, kshier, mvyas, neugens, pjindal, stcannon, teagle, tpopela, yguenane
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A heap based buffer overflow flaw has been discovered in LibPNG. Prior to version 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.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2438653, 2438654, 2438656, 2438657, 2438659, 2438660, 2438661, 2438662, 2438664, 2438665, 2438666, 2438667, 2438668, 2438669, 2438670, 2438671, 2438672, 2438674, 2438675, 2438676, 2438677, 2438678, 2438679, 2438680, 2438681, 2438682, 2438683, 2438684, 2438686, 2438655, 2438658, 2438663, 2438673, 2438685
Bug Blocks:

Description OSIDB Bzimport 2026-02-10 18:01:50 UTC

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.