CVE-2026-125233

FFmpeg through 9.0.2 Heap Buffer Overflow via DVB Subtitle Encoder

Published Nov 9, 2026 CVSS 4.0 · 8.5 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
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.
Title FFmpeg through 9.0.2 Heap Buffer Overflow via DVB Subtitle Encoder
First Time appeared Ffmpeg
Ffmpeg ffmpeg
Weaknesses CWE-131
CPEs cpe:2.3:a:ffmpeg:ffmpeg:*:*:*:*:*:*:*:*
Vendors & Products Ffmpeg
Ffmpeg ffmpeg
References
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.5, 'vector': '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Nov 9, 2026, 7:11 PM
Reserved
Nov 9, 2026, 6:15 PM
Status
Awaiting Analysis
Published
Nov 9, 2026, 7:17 PM
Modified
Nov 10, 2026, 9:46 PM