CVE-2026-96611 Integer overflow in FFmpeg

Medium 6.9 Published 23 Sep 2026 Updated 26 Sep 2026

An attacker can cause a signed integer overflow in FFmpeg's HEIF parser, potentially leading to denial of service or code execution via crafted media files.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2026-96611?

CVE-2026-96611 is a medium-severity vulnerability in Ffmpeg Ffmpeg, published on 23 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

FFmpeg before 9.0 has a signed integer overflow in libavformat/mov.c. In mov_read_ispe(), uint32_t width/height values from a crafted HEIF ispe box are stored into signed int fields without bounds checking, allowing values exceeding INT_MAX to become negative. In read_image_grid(), accumulating these values causes signed integer overflow (undefined behavior per C17 section 6.5), which on x86 wraps to a small positive value, bypassing downstream validity checks.

Weakness: CWE-190

Which versions are affected by CVE-2026-96611?

It affects 1 product.

Products include Ffmpeg Ffmpeg.

How do I fix CVE-2026-96611?

Upgrade to a fixed version.

Is CVE-2026-96611 being exploited?

There is no known exploitation of CVE-2026-96611 in the wild and no public exploit code.

All Ffmpeg Ffmpeg vulnerabilities

Sources

Also known as DEBIAN-CVE-2026-96611, GHSA-g222-rpm9-83x6, UBUNTU-CVE-2026-96611.