CVE-2026-125269 PUBLISHED

FFmpeg through 9.0.2 Double Free via cbs_sei_delete_message in cbs_sei.c

Assigner: VulnCheck
Reserved: 09.11.2026 Published: 09.11.2026 Updated: 09.11.2026

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.

CVSS 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
CVSS Score: 7.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Local	Confidentiality	High	Confidentiality	None
Attack Complexity	High	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	High	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS Score: 7

Attack Vector	Local	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	Required	Availability Impact	High

CVSS 3.1

Product Status

Vendor	FFmpeg
Product	FFmpeg
Versions	Default: unaffected affected from 0 to 9.0.2 (incl.)

CVE-2026-125269 PUBLISHED

FFmpeg through 9.0.2 Double Free via cbs_sei_delete_message in cbs_sei.c

Metrics

Product Status

Credits

References

Problem Types