CVE-2026-125203
FFmpeg before 8.1.3 and 9.x before 9.0.2 Heap Buffer Overflow in Cook Multichannel Decoder
CVSS Score
7.8
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-787 |
| Vendor | ffmpeg |
| Product | ffmpeg |
| Published | Nov 9, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
FFmpeg / FFmpeg
0 < 8.1.3 9.0 < 9.0.2
References
code.ffmpeg.org: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24485 github.com: https://github.com/FFmpeg/FFmpeg/commit/3e09f5e24eb277a6d011745ff03e602f61c5c171 github.com: https://github.com/FFmpeg/FFmpeg/blob/n9.0.1/libavcodec/cook.c#L1294 github.com: https://github.com/FFmpeg/FFmpeg vulncheck.com: https://www.vulncheck.com/advisories/ffmpeg-before-8.1.3-and-9-x-before-9.0.2-heap-buffer-overflow-in-cook-multichannel-decoder
Credits
Zheng Yu @ Depthfirst 🔍 Joshua Rogers (AISLE Research) Michael Niedermayer