CVE-2026-125189: FFmpeg · Reachable Assertion
Affects FFmpegSource CVE Database V5
Not known to be exploited · CVSS 5.7 Medium.
Data as of 9 Nov 2026, 20:33 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 5.7 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 4.7 |
CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 9 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 9 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| FFmpegFFmpeg | Affected
| Fixed in– |
GitHubFFmpegpkg:github/FFmpegOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is available, avoid processing untrusted LCEVC bitstreams or apply other operational mitigations as appropriate.
Description
FFmpeg versions 8.1 through 9.0.2 contain a denial of service vulnerability in the lcevc_metadata bitstream filter. This flaw is due to a process block position mismatch in the function lcevc_metadata_handle_vui(), which can be triggered by specially crafted LCEVC access units containing two IDR or non-IDR NAL units. Exploitation causes an assertion failure leading to application abort.
References
- code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25408 (opens in a new tab)
- github.com/FFmpeg/FFmpeg/commit/0747459f0c6f228566f5cb11ceed56b977208582 (opens in a new tab)
- github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/bsf/lcevc_metadata.c (opens in a new tab)
- github.com/FFmpeg/FFmpeg (opens in a new tab)
- vulncheck.com/advisories/ffmpeg-8.1-through-9.0.2-denial-of-service-via-lcevc-metadata-bitstream-filter (opens in a new tab)