Vulnerability in Ffmpeg
CVE-2026-125266
FFmpeg through 9.0.2 contains an uninitialized stack memory disclosure vulnerability in old_codec23() of libavcodec/sanm.c that leaks stack bytes into decoded frames. Attackers can supply a crafted LucasArts SMUSH/SANM animation using codec 23 with an inline table to expose decoder process stack memory in output video.
Published .
CVSS v3 metric
CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N.
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/25718 (issue-tracking)
- github.com/FFmpeg/FFmpeg/commit/d42cb1925987cc27899441ce39fa7bd2647dc72e (patch)
- github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/sanm.c (technical-description)
- github.com/FFmpeg/FFmpeg (product)
- www.vulncheck.com/advisories/ffmpeg-through-9.0.2-uninitialized-stack-memory-di… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-125266?
- CVE-2026-125266 is a low-severity vulnerability in Ffmpeg, classified under Use of Uninitialized Resource. CVSS score: 3.3/10. Published 2026-11-09.
- How severe is CVE-2026-125266?
- Low severity. CVSS v3 base score is 3.3 out of 10.