Buffer overflow in Ffmpeg
CVE-2026-70632
FFmpeg versions from 4.4 up to, but not including, 9.0 contain an out-of-bounds heap write vulnerability in the native GoPro CineForm HD (CFHD) decoder that allows remote attackers to corrupt heap memory by supplying a crafted AVI file during stream probing. The cfhd_decode() function fails to enforce the non-Bayer logical output-width invariant in the transform-type-2 reconstruction path, causing horiz_filter_clip() to write oversized 16-bit sample rows far beyond the allocated output frame buffer, which can be escalated to arbitrary code execution via overwrite of a live cleanup callback pointer.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.002 (13.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 13.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
- Ffmpeg — versions 4.4
Weakness classification (CWE)
References
- code.ffmpeg.org/FFmpeg/FFmpeg/commit/1006a2151236f9235bf02822f263b3fb0532111e (related, Patch)
- code.ffmpeg.org/FFmpeg/FFmpeg/commit/16b2049d4d5222db6cd7c031409058571c94f6a9 (Patch, patch)
- code.ffmpeg.org/FFmpeg/FFmpeg/commit/db05df9d135fb56a4babb836d5e9f5c1d984e087 (Patch, patch)
- code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23898 (issue-tracking, Patch, Issue Tracking)
- www.vulncheck.com/advisories/ffmpeg-heap-out-of-bounds-write-in-cfhd-decoder-vi… (Patch, Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-70632?
- CVE-2026-70632 is a high-severity vulnerability in Ffmpeg, classified under Out-of-bounds Write. CVSS score: 7.8/10. Published 2026-08-06.
- How severe is CVE-2026-70632?
- High severity. CVSS v3 base score is 7.8 out of 10.