Description
FFmpeg through 9.0.2 contains an integer underflow in decode_frame() in libavcodec/lcldec.c that allows attackers to trigger a heap out-of-bounds read via short ZLIB packets with FLAG_MULTITHREAD. Attackers can supply a crafted AVI or MKV file with an LCL video stream whose packet is shorter than 8 bytes, bypassing length clamping to crash the decoding application.
Metrics
CVSS 3.1 6.1/10
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:HWeakness enumeration
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| FFmpeg | FFmpeg | <= 9.0.2 |
References
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25020
- https://github.com/FFmpeg/FFmpeg
- https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/lcldec.c#L287
- https://github.com/FFmpeg/FFmpeg/commit/12e5d4ec98b7add7bcac9d8131d9a6dfb2549966
- https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-heap-out-of-bounds-read-via-lcl-zlib-multithread-decoding
Timeline
- Published
- Nov 9, 2026
- Last modified
- Nov 14, 2026
- NVD status
- Undergoing Analysis