CVE-2026-66036

Description

FFmpeg through 8.1.2, fixed in commit 5d7112c, contains a heap out-of-bounds write vulnerability in the vf_hqdn3d filter that allows attackers to corrupt heap memory by supplying a crafted video whose frame resolution increases between frames when filtergraph reinitialization is disabled via the -reinit_filter 0 option. Attackers can provide a malicious video input where vf_hqdn3d.config_input() allocates undersized per-plane line-history buffers based on the initial frame width, and subsequent larger frames cause denoise_spatial() to write beyond the allocation boundary, resulting in heap memory corruption.

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Severity score breakdown

CVSS version: CVSS v4.0 CVSS v4.0 CVSS v3.0

References

• MITRE
• NVD
• Launchpad
• Debian

Related Ubuntu Security Notices (USN)

• USN-8671-1
• FFmpeg vulnerabilities
• 24 August 2026

Other references

• https://www.cve.org/CVERecord?id=CVE-2026-66036
• https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23783
• https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/5d7112c60e6f0f0742ce47d448e6da0718a70f4c
• https://www.vulncheck.com/advisories/ffmpeg-heap-out-of-bounds-write-in-vf-hqdn3d-filter