Buffer overflow in Ffmpeg
CVE-2026-125239
FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in ff_dxva2_hevc_fill_picture_parameters() that allows attackers to corrupt memory via unbounded non-uniform tile counts. Attackers can supply crafted HEVC bitstreams with many non-uniformly spaced tiles to write controlled 16-bit values past fixed-size DXVA arrays during DXVA2, D3D11VA, or D3D12VA decoding on Windows.
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/25136 (issue-tracking)
- github.com/FFmpeg/FFmpeg (product)
- github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/dxva2_hevc.c (technical-description)
- www.vulncheck.com/advisories/ffmpeg-through-9.0.2-heap-buffer-overflow-via-hevc… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-125239?
- CVE-2026-125239 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-2026-125239?
- High severity. CVSS v3 base score is 7.0 out of 10.