CVE-2026-75146

Name	CVE-2026-75146
Description	FFmpeg before commit 65b0dab contains an out-of-bounds read in the DASH demuxer (libavformat/dashdec.c). When a live DASH manifest is refreshed with a startNumber that is lower than the previous value, the current sequence number is driven negative. The fragment retrieval function checked only the upper bound before indexing the fragments array, allowing a negative index to be used and causing an out-of-bounds read. A malicious or misconfigured DASH server can trigger this by serving a live manifest with a decreasing startNumber across a manifest refresh.
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)	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)

Notes

[trixie] - ffmpeg <postponed> (Wait until fixed in 7.1.x upstream branch)
https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24093
Fixed by: https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/65b0dab903e5975e036b30ecc58f5935d4f151e0 (master)
Fixed by: https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/999f8ba75ce0bf1167677de7e11a5af678fdb866 (n9.0.1)