Answer in brief
CVE-2026-125203 records a High severity (CVSS 8.5) vulnerability in FFmpeg before 8.1.3 and 9.x before 9.0.2 Heap Buffer Overflow in Cook Multichannel Decoder. The current sources do not mark it as known exploited. The current feed maps FFmpeg/FFmpeg (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps FFmpeg/FFmpeg (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| FFmpeg/FFmpeggeneric | >=0 <8.1.3 || >=9.0 <9.0.2 | 8.1.3, 9.0.2 |
Published upstream
Nov 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 9, 2026
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.
Quoted source text, attributed separately from HOL analysis.