CVE-2026-112898

Name	CVE-2026-112898
Description	Pillow is a Python imaging library. From 9.1.0 until 13.0.0, Pillow can disclose uninitialized stack memory when Image.quantize() uses an empty palette. ImagingPaletteCacheUpdate() leaves a local cache array uninitialized when the palette has zero entries, and the conversion path emits those bytes as output pixel indices. An attacker who controls the palette image can obtain stack contents from a returned PNG or GIF. This can disclose addresses and stack-canary data without an out-of-bounds access, memory corruption, or process crash. This issue is fixed in version 13.0.0.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
pillow (PTS)	bookworm, bookworm (security)	9.4.0-1.1+deb12u1	vulnerable
	trixie	11.1.0-5+deb13u4	vulnerable
	trixie (security)	11.1.0-5+deb13u3	vulnerable
	forky, sid	12.3.0-1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
pillow	source	(unstable)	(unfixed)

Notes

https://github.com/python-pillow/Pillow/security/advisories/GHSA-rfgq-q3w2-pmv2
Fixed by: https://github.com/python-pillow/Pillow/commit/13943c8f857b22f073d30f0ef9b725a0d255f1a4 (13.0.0)