CVE-2026-66036

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-24 20:18 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-08-07 01:05 UTC Last updatedMost recent change to the record

Details

Published

2026-07-24 20:18 UTC

Last modified

2026-08-07 01:05 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-122

Record status

Analyzed

Affected

• Ffmpeg ≤ 8.1.2

Attack profile CVSS 4.0 · 7.7

Attack vector

Network

Complexity

Low

Attack requirements

Present

Privileges needed

None

User interaction

Passive

Confidentiality

High

Integrity

High

Availability

High