CVE-2026-125269

high

Description

FFmpeg through 9.0.2 contains a double free vulnerability in libavcodec/cbs_sei.c where cbs_sei_delete_message() leaves a stale extension_data reference that ff_cbs_sei_add_message() reuses. Attackers can supply a crafted H.264 stream with a display orientation SEI message followed by payload extension data, processed by h264_metadata with display_orientation=insert, to corrupt heap memory.

References

https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-double-free-via-cbs-sei-delete-message-in-cbs-sei-c

https://github.com/FFmpeg/FFmpeg/commit/2c515eea07df719379e7f73deeeb7ccb8768433f

https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/cbs_sei.c#L287

https://github.com/FFmpeg/FFmpeg

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-120219

https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25020

Details

Source: Mitre, NVD

Published: 2026-11-09

Updated: 2026-11-10

Risk Information

CVSS v2

Base Score: 6.2

Vector: CVSS2#AV:L/AC:H/Au:N/C:C/I:C/A:C

Severity: Medium

CVSS v3

Base Score: 7

Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Severity: High

CVSS v4

Base Score: 7.3

Vector: CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.00129