CVE-2026-12891

Name	CVE-2026-12891
Description	A flaw was found in the GStreamer gst-plugins-bad package. When processing a malformed H.266/VVC video stream with a crafted aspect ratio indicator value, the H.266 parser performs an out-of-bounds read of up to 8 bytes from adjacent memory. This flaw allows an attacker to craft a malicious H.266 video file or stream that, when processed by a GStreamer-based application, could leak limited memory contents through video metadata, potentially exposing sensitive information from the application's address space.
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
gst-plugins-bad1.0 (PTS)	bullseye	1.18.4-3+deb11u4	vulnerable
	bullseye (security)	1.18.4-3+deb11u6	vulnerable
	bookworm, bookworm (security)	1.22.0-4+deb12u7	vulnerable
	trixie	1.26.2-3+deb13u1	vulnerable
	trixie (security)	1.26.2-3+deb13u2	vulnerable
	forky, sid	1.28.4-1	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
gst-plugins-bad1.0	source	(unstable)	(unfixed)

https://bugzilla.redhat.com/show_bug.cgi?id=2491318
https://gitlab.freedesktop.org/gstreamer/gstreamer/-/work_items/5109 (private)