Quick answers
- Is CVE-2026-125254 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-125254 being exploited in the wild.
- How severe is CVE-2026-125254?
- Medium severity, with a CVSS score of 5.5, published 9 November 2026.
- Which products and versions are affected?
- Ffmpeg through 9.0.2.
- Is there a fix for CVE-2026-125254?
- Yes: fixed in FFmpeg 9.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-125254 attacked?
- It is attacked over the network or with local access, in a software library.
- Am I affected by CVE-2026-125254?
- Check whether you run Ffmpeg at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: FFmpeg 9.1
Technical details
The VVC decoder in FFmpeg fails to validate that the number of active reference indices does not exceed the number of reference list entries in ff_vvc_slice_rpl(), resulting in a division by zero in ff_vvc_mv_scale() when processing a crafted bitstream. An attacker can supply a malicious VVC video file that triggers this crash via network delivery or as a local file. The vulnerability is fixed by rejecting slices where num_ref_entries is less than NumRefIdxActive as required by the H.266 specification.
Affected products
- FFmpeg FFmpeg through 9.0.2
Timeline
- 2026-11-09: disclosed
- 2026-11-03: patched: Fix merged in PR #25572