Description
FFmpeg before 8.1.3 and 9.x before 9.0.2 contains a heap buffer overflow vulnerability in the Cook multichannel decoder in libavcodec/cook.c that fails to verify subpacket channel masks are disjoint. Attackers can supply a crafted RealMedia Cook stream with overlapping subpacket masks, causing cook_decode_frame() to write decoded samples beyond allocated output planes in any application decoding the file.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| FFmpeg | FFmpeg | < 8.1.3, 9.0 – < 9.0.2 | 8.1.3 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | ffmpeg | 7:9.0.2-1 | — |
| Debian 13 | ffmpeg | No fix yet | — |
| Debian 12 | ffmpeg | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | ffmpeg | No fix yet | — |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 26.04 LTS | ffmpeg | No fix yet | — |
| Ubuntu Pro 24.04 LTS | ffmpeg | No fix yet | — |
| Ubuntu Pro 22.04 LTS | ffmpeg | No fix yet | — |
| Ubuntu Pro 20.04 LTS | ffmpeg | No fix yet | — |
| Ubuntu Pro 18.04 LTS | ffmpeg | No fix yet | — |
| Ubuntu Pro 16.04 LTS | ffmpeg | No fix yet | — |
Advisories 1
- WID-SEC-2026-4419 ffmpeg: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 9, 2026
References
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24485 issue-tracking
- Patch Commit patch
- https://github.com/FFmpeg/FFmpeg/blob/n9.0.1/libavcodec/cook.c#L1294 technical-description
- https://github.com/FFmpeg/FFmpeg product
- VulnCheck Advisory: FFmpeg before 8.1.3 and 9.x before 9.0.2 Heap Buffer Overflow in Cook Multichannel Decoder third-party-advisory