CVE-2026-125233
FFmpeg through 9.0.2 Heap Buffer Overflow via DVB Subtitle Encoder
CVSS Score
7.8
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-131 |
| Vendor | ffmpeg |
| Product | ffmpeg |
| Published | Nov 9, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
FFmpeg / FFmpeg
0 ≤ 9.0.2
References
code.ffmpeg.org: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24913 github.com: https://github.com/FFmpeg/FFmpeg/commit/7f80b2ad83f37a4998d9617495c92b28a7339a90 github.com: https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/dvbsubenc.c#L363 github.com: https://github.com/FFmpeg/FFmpeg vulncheck.com: https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-heap-buffer-overflow-via-dvb-subtitle-encoder
Credits
Secbuddy, Tencent Keen Security Lab (tested by kvartet) 🔍 Joshua Rogers (AISLE Research) Michael Niedermayer