Out-of-bounds Read in Ffmpeg
CVE-2026-125172
FFmpeg through 9.0.2 contains an out-of-bounds read vulnerability in libxevd_receive_frame() in libavcodec/libxevd.c that fails to validate NAL unit length prefixes against remaining packet data. Attackers can supply crafted EVC media with oversized 4-byte NAL length prefixes, causing libxevd to read past the packet buffer, crashing the application or exposing adjacent heap memory.
Vulnerability class: Buffer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/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/25416 (issue-tracking)
- github.com/FFmpeg/FFmpeg (product)
- github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/libxevd.c (technical-description)
- github.com/FFmpeg/FFmpeg/commit/e06b3953d4253f8b56271628ba4083fde96aeadb (patch)
- www.vulncheck.com/advisories/ffmpeg-through-9.0.2-out-of-bounds-read-via-libxev… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-125172?
- CVE-2026-125172 is a medium-severity vulnerability in Ffmpeg, classified under Out-of-bounds Read. CVSS score: 6.1/10. Published 2026-11-09.
- How severe is CVE-2026-125172?
- Medium severity. CVSS v3 base score is 6.1 out of 10.