# CVE-2026-96611: ffmpeg: FFmpeg before 9.0 has a signed integer overflow in libavformat/mov.c

CVE-2026-96611 is fixed in ffmpeg on 1 platform, first by DEBIAN-CVE-2026-96611, released September 24, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-96611
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0011
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 23, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | ffmpeg Debian 13.5 (trixie) | 7:7.1.5-0+deb13u1 | [DEBIAN-CVE-2026-96611](https://patchblox.com/security/data/fix/linux/debian-cve-2026-96611.md) | Sep 24, 2026 |
| Linux | ffmpeg Debian 14 | 7:8.1.2-1 | [DEBIAN-CVE-2026-96611](https://patchblox.com/security/data/fix/linux/debian-cve-2026-96611.md) | Sep 24, 2026 |

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Data as of 2026-11-09T19:38:12Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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