{"id":"CVE-2026-125203","title":"FFmpeg before 8.1.3 and 9.x before 9.0.2 Heap Buffer Overflow in Cook Multichannel Decoder","summary":"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 RealMe…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-787"],"vendor":"FFmpeg","product":"FFmpeg","affected":["FFmpeg < 8.1.3","FFmpeg >= 9.0 < 9.0.2"],"published":"2026-11-09","updated":"2026-11-09","sourceUpdated":"2026-11-09T19:11:22.136Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-125203","references":[{"url":"https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24485"},{"url":"https://github.com/FFmpeg/FFmpeg/commit/3e09f5e24eb277a6d011745ff03e602f61c5c171","label":"Patch Commit"},{"url":"https://github.com/FFmpeg/FFmpeg/blob/n9.0.1/libavcodec/cook.c#L1294"},{"url":"https://github.com/FFmpeg/FFmpeg"},{"url":"https://www.vulncheck.com/advisories/ffmpeg-before-8.1.3-and-9-x-before-9.0.2-heap-buffer-overflow-in-cook-multichannel-decoder","label":"VulnCheck Advisory: FFmpeg before 8.1.3 and 9.x before 9.0.2 Heap Buffer Overflow in Cook Multichannel Decoder"}],"tags":["cve.org"],"ingestedAt":"2026-11-09T19:18:02.598Z","slug":"CVE-2026-125203","body":"## Overview\n\nFFmpeg 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.\n\n## Affected\n\n- `FFmpeg < 8.1.3`\n- `FFmpeg >= 9.0 < 9.0.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}