Vulnerability in Ffmpeg
CVE-2026-125174
FFmpeg before 8.1.3 and 9.x before 9.0.2 contains a NULL pointer dereference vulnerability in ff_hap_set_chunk_count() in libavcodec/hap.c, where a shadowed return variable masks reallocation failures. Attackers can supply a crafted Hap video frame with an oversized chunk count so the decoder writes through a NULL chunk table, crashing the application.
Published .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24487 (issue-tracking)
- github.com/FFmpeg/FFmpeg (product)
- github.com/FFmpeg/FFmpeg/blob/n9.0.1/libavcodec/hap.c (technical-description)
- Patch Commit (patch)
- VulnCheck Advisory: FFmpeg before 8.1.3 and 9.x before 9.0.2 NULL Pointer Dereference via ff_hap_set_chunk_count() (third-party-advisory)
Frequently asked questions
- What is CVE-2026-125174?
- CVE-2026-125174 is a medium-severity vulnerability in Ffmpeg, classified under CWE-252. CVSS score: 5.5/10. Published 2026-11-09.
- How severe is CVE-2026-125174?
- Medium severity. CVSS v3 base score is 5.5 out of 10.