What’s Vulnerable › Vulnerabilities

CVE-2026-70632: FFmpeg 4.4 < 9.0 Heap Out-of-Bounds Write in CFHD Decoder via AVI Demuxing

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-06 · updated 2026-09-01
• Weakness: CWE-787

Description

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.

Affected products

• FFmpeg: from 4.4 before 9 — fixed in 9

How to fix

Upgrade to a fixed version: FFmpeg 9. Check the vendor advisory for mitigations.

References

• https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/1006a2151236f9235bf02822f263b3fb0532111e
• https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/16b2049d4d5222db6cd7c031409058571c94f6a9
• https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/db05df9d135fb56a4babb836d5e9f5c1d984e087
• https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23898
• https://www.vulncheck.com/advisories/ffmpeg-heap-out-of-bounds-write-in-cfhd-decoder-via-avi-demuxing

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