Integer overflow in Ffmpeg
CVE-2026-125227
FFmpeg through 9.0.2 contains an integer overflow in cbs_jpeg_write_scan() in libavcodec/cbs_jpeg.c that causes a heap buffer overflow on 32-bit builds. Attackers can supply a crafted MJPEG/JPEG stream with a scan of 512 MiB or more, processed by CBS bitstream filters like filter_units, to corrupt the heap or crash the application.
Vulnerability class: Integer 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/25232 (issue-tracking)
- github.com/FFmpeg/FFmpeg (product)
- github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/cbs_jpeg.c (technical-description)
- github.com/FFmpeg/FFmpeg/commit/b89ce54d93bf644433dfa9fbc34f19c22237691a (patch)
- www.vulncheck.com/advisories/ffmpeg-through-9.0.2-heap-buffer-overflow-via-cbs-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-125227?
- CVE-2026-125227 is a high-severity vulnerability in Ffmpeg, classified under Integer Overflow or Wraparound. CVSS score: 7.0/10. Published 2026-11-09.
- How severe is CVE-2026-125227?
- High severity. CVSS v3 base score is 7.0 out of 10.