CVE-2026-64830

Name	CVE-2026-64830
Description	FFmpeg versions 2.1 through 8.1.2 contains a heap buffer overflow vulnerability in the VobSub subtitle demuxer that allows attackers to corrupt adjacent heap memory by supplying a malicious .sub/.idx subtitle file declaring more distinct stream IDs than the fixed-size array bounds in libavformat/mpeg.c. Attackers can craft a subtitle file with excessive distinct stream IDs to trigger unbounded writes beyond the vobsub->q[] array boundary via ff_subtitles_queue_insert(), potentially achieving arbitrary code execution in any application using FFmpeg's VobSub demuxer.
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
ffmpeg (PTS)	bullseye	7:4.3.7-0+deb11u1	vulnerable
	bullseye (security)	7:4.3.9-0+deb11u2	vulnerable
	bookworm, bookworm (security)	7:5.1.9-0+deb12u1	vulnerable
	trixie (security), trixie	7:7.1.5-0+deb13u1	vulnerable
	forky, sid	7:8.1.2-2	vulnerable

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

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

https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23657
Fixed by: https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/dbd495f066a85ba96b17433f4306582aa37c3951