CVE-2026-125191
FFmpeg through 9.0.2 V4L2 M2M Decoder Deadlock via Reference Count Leak
FFmpeg through 9.0.2 contains a reference count leak in libavcodec/v4l2_buffers.c that allows attackers to deadlock the V4L2 mem2mem decoder on multi-plane capture formats. Attackers can supply crafted H.264, HEVC, or VP9 streams with resolution changes, making ff_v4l2_m2m_codec_reinit() wait forever and hang the decoding application.
Fixes and workarounds
Fix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: VulnCheckAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| FFmpeg FFmpeg ffmpeg/ffmpeg
github |
≥ 0; ≤ 9.0.2 (affected, semver)
Other versions: unaffected |
CNA: VulnCheck |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 5.7 medium |
CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | CNA: VulnCheck |
| 3.1 / 4.7 medium |
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H | CNA: VulnCheck |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25682CNA: VulnCheck · issue-tracking
- https://github.com/FFmpeg/FFmpeg/commit/4d2d58efa9b9f3802893b1db0ea1edfbe1cc66efCNA: VulnCheck · patch
- https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/v4l2_buffers.c#L274CNA: VulnCheck · technical-description
- https://github.com/FFmpeg/FFmpegCNA: VulnCheck · product
- https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-v4l2-m2m-decoder-deadlock-via-reference-count-leakCNA: VulnCheck · third-party-advisory
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