Buffer overflow in Ffmpeg
CVE-2026-125208
FFmpeg through 9.0.2 contains an out-of-bounds write vulnerability in v4l2_buffer_swframe_to_buf() in libavcodec/v4l2_buffers.c because cumulative plane offsets are not checked against the V4L2 buffer length. Attackers can supply crafted video whose dimensions or padding cause unsigned wraparound in v4l2_bufref_to_buf(), making memcpy() write past the mmaped driver buffer during V4L2 M2M encoding.
Vulnerability class: Buffer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/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/24328 (issue-tracking)
- github.com/FFmpeg/FFmpeg (product)
- github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/v4l2_buffers.c (technical-description)
- github.com/FFmpeg/FFmpeg/commit/b8f159858e2fd29dae4fa34d9e713bbf9bbf190e (patch)
- www.vulncheck.com/advisories/ffmpeg-through-9.0.2-v4l2-m2m-encoder-out-of-bound… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-125208?
- CVE-2026-125208 is a high-severity vulnerability in Ffmpeg, classified under Out-of-bounds Write. CVSS score: 7.0/10. Published 2026-11-09.
- How severe is CVE-2026-125208?
- High severity. CVSS v3 base score is 7.0 out of 10.