CVE-2026-59197

Name	CVE-2026-59197
Description	Pillow is a Python imaging library. Prior to 12.3.0, Pillow's public rank-filter API can trigger a native heap out-of-bounds write when given a very large odd filter size because ImageFilter.RankFilter.filter() calls image.expand(size // 2, size // 2) before rank-filter size validation and ImagingExpand() computes output dimensions with unchecked signed int arithmetic. This issue is fixed in version 12.3.0.
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)	bullseye	8.1.2+dfsg-0.3+deb11u2	vulnerable
	bullseye (security)	8.1.2+dfsg-0.3+deb11u3	vulnerable
	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	12.2.0-1	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-xj96-63gp-2gmr
https://github.com/python-pillow/Pillow/pull/9695
Fixed by: https://github.com/python-pillow/Pillow/commit/cce3bdb867c77a3420261ed1bfdb6b0787ec8fc1 (12.3.0)