{"id":"CVE-2026-125203","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-125203","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…","details":"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.","published":"2026-11-09T19:16:56.740","modified":"2026-11-09T19:16:56.740","cvss":{"score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":{"url":"https://github.com/FFmpeg/FFmpeg/commit/3e09f5e24eb277a6d011745ff03e602f61c5c171","label":"FFmpeg/FFmpeg@3e09f5e"},"references":[{"type":"WEB","url":"https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24485"},{"type":"WEB","url":"https://github.com/FFmpeg/FFmpeg"},{"type":"WEB","url":"https://github.com/FFmpeg/FFmpeg/blob/n9.0.1/libavcodec/cook.c#L1294"},{"type":"WEB","url":"https://github.com/FFmpeg/FFmpeg/commit/3e09f5e24eb277a6d011745ff03e602f61c5c171"},{"type":"WEB","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"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-11-09T19:16:56.740"}}