CVE-2026-125233
Discovered by AISLEPUBLISHEDCWE-131
Description
FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in dvbsub_encode() in libavcodec/dvbsubenc.c that undercounts each CLUT segment header by two bytes. Attackers can supply a file with many bitmap subtitle rectangles that, when transcoded to the dvbsub encoder, writes past the output buffer and corrupts heap memory.
CVSS Base Scores
CVSS v4.08.5
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS v3.1
7.8CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Affected Products
| Vendor | Product | Version | Status |
|---|---|---|---|
| FFmpeg | FFmpeg | 0 | affected |
Credits
- Secbuddy, Tencent Keen Security Lab (tested by kvartet)(finder)
- Joshua Rogers (AISLE Research)(reporter)
- Michael Niedermayer(remediation developer)
References
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24913
- https://github.com/FFmpeg/FFmpeg/commit/7f80b2ad83f37a4998d9617495c92b28a7339a90
- https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/dvbsubenc.c#L363
- https://github.com/FFmpeg/FFmpeg
- https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-heap-buffer-overflow-via-dvb-subtitle-encoder