Integer overflow in Ffmpeg
CVE-2026-125249
FFmpeg 7.1 through 9.0.2 contains an integer overflow in ff_vk_decode_add_slice() in libavcodec/vulkan_decode.c that miscalculates the Vulkan hwaccel bitstream buffer size. Attackers can supply a crafted stream with over 2 GiB of slice data per frame, causing memcpy() to write past a smaller pooled host-mapped buffer.
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/25136 (issue-tracking)
- github.com/FFmpeg/FFmpeg (product)
- github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/vulkan_decode.c (technical-description)
- www.vulncheck.com/advisories/ffmpeg-7.1-through-9.0.2-heap-out-of-bounds-write-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-125249?
- CVE-2026-125249 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-2026-125249?
- High severity. CVSS v3 base score is 7.0 out of 10.