CVE-2026-125199: FFmpeg · Memory Leak
Affects FFmpegSource CVE Database V5
Not known to be exploited · CVSS 6.8 Medium.
Data as of 9 Nov 2026, 20:32 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 6.8 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 5.5 |
CVSS:4.0/AV:L/AC:L/AT:N/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, users should avoid processing untrusted VC-1 video files with affected FFmpeg versions to mitigate risk.
Description
CVE-2026-125199 is a medium severity memory leak vulnerability in FFmpeg versions 8.1 through 9.0.2. It occurs in the vc1_decode_frame() function of libavcodec/vc1dec.c, where slice buffers are leaked if init_get_bits8() fails. Crafted files with repeated oversized VC-1 slices can trigger this leak, potentially exhausting the memory of applications that decode such files.
References
- code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25718 (opens in a new tab)
- github.com/FFmpeg/FFmpeg/commit/afdc555aace698b88c86d3f33a7773a6c8ba2897 (opens in a new tab)
- github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/vc1dec.c (opens in a new tab)
- github.com/FFmpeg/FFmpeg (opens in a new tab)
- vulncheck.com/advisories/ffmpeg-through-9.0.2-memory-leak-in-vc-1-decoder-via-vc1-decode-frame (opens in a new tab)