What’s Vulnerable › Vulnerabilities

CVE-2026-66036: FFmpeg Heap Out-of-Bounds Write in vf_hqdn3d Filter

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-24 · updated 2026-08-07
• Weakness: CWE-122

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.

Affected products

• FFmpeg: through 8.1.2

References

• https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/5d7112c60e6f0f0742ce47d448e6da0718a70f4c
• https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23783
• https://www.vulncheck.com/advisories/ffmpeg-heap-out-of-bounds-write-in-vf-hqdn3d-filter

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