Vulnerability in Ffmpeg
CVE-2026-125191
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.
Published .
CVSS v3 metric
CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25682 (issue-tracking)
- github.com/FFmpeg/FFmpeg (product)
- github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/v4l2_buffers.c (technical-description)
- Patch Commit (patch)
- VulnCheck Advisory: FFmpeg through 9.0.2 V4L2 M2M Decoder Deadlock via Reference Count Leak (third-party-advisory)
Frequently asked questions
- What is CVE-2026-125191?
- CVE-2026-125191 is a medium-severity vulnerability in Ffmpeg, classified under CWE-911. CVSS score: 4.7/10. Published 2026-11-09.
- How severe is CVE-2026-125191?
- Medium severity. CVSS v3 base score is 4.7 out of 10.