CVE-2026-66036: FFmpeg heap out-of-bounds write in vf_hqdn3d filter

CVE-2026-66036 · Severity: high · CVSS 8.8 · Published 2026-07-24

FFmpeg, a widely used multimedia framework for processing video and audio, contains a security flaw in its high-quality denoising filter (hqdn3d). An attacker can provide a specially crafted video file that, when processed with specific settings, causes the software to crash or potentially execute unauthorized code. This could lead to a total compromise of the system processing the video or the theft of sensitive data.

Technologies: Ffmpeg. Vendors: Ffmpeg.

Quick answers

Is CVE-2026-66036 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-66036 being exploited in the wild.
How severe is CVE-2026-66036?
High severity, with a CVSS score of 8.8, published 24 July 2026.
Which products and versions are affected?
Ffmpeg through 8.1.2.
Is there a fix for CVE-2026-66036?
A patch was published on 2026-07-12: Fix committed to FFmpeg master branch Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-66036 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-66036?
Check whether you run Ffmpeg at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A heap-based buffer overflow exists in FFmpeg's vf_hqdn3d filter due to improper handling of dynamic frame resolution changes. When filtergraph reinitialization is disabled (via -reinit_filter 0), the vf_hqdn3d.config_input() function may allocate line-history buffers based on an initial small frame size. If a subsequent frame in the same stream has a larger resolution, the denoise_spatial() function writes data into these undersized buffers, leading to an out-of-bounds write. This can result in heap memory corruption, application crashes, or arbitrary code execution. The vulnerability is fixed in commit 5d7112c.

Affected products

  • FFmpeg FFmpeg through 8.1.2

Timeline

  • 2026-07-12: patched: Fix committed to FFmpeg master branch
  • 2026-07-24: disclosed: CVE-2026-66036 published

References

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