FFmpeg: Heap memory corruption via double free vulnerability (CVE-2026-125269)
FFmpeg through 9.0.2 contains a double free vulnerability in libavcodec/cbs_sei.c that allows heap memory corruption via crafted H.264 streams.
CVE search metadata
CVE search record: CVE-2026-125269. Severity: high. CVSS: 7.0. KEV: no. Product: FFmpeg (through 9.0.2). Brief: FFmpeg: Heap memory corruption via double free vulnerability (CVE-2026-125269). Brief link: https://feed.craftedsignal.io/briefs/2026-11-ffmpeg-double-free/
Triage facts
Revision 1- Applicability
- FFmpeg (through 9.0.2)
- Evidence
- Unknown
- Severity
- High
- Sources
- 1 public source
- Freshness
- Revision 1Nov 9, 23:59 UTC
- Vulnerabilities
- 1 CVE
- Source quality
- A2Roughly even chance
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.