CVE-2026-75146: Ffmpeg

High severity, CVSS 8.1. EPSS: 0.3% chance of exploitation in the next 30 days.

FFmpeg before commit 65b0dab contains an out-of-bounds read in the DASH demuxer (libavformat/dashdec.c). When a live DASH manifest is refreshed with a startNumber that is lower than the previous value, the current sequence number is driven negative. The fragment retrieval function checked only the upper bound before indexing the fragments array, allowing a negative index to be used and causing an out-of-bounds read. A malicious or misconfigured DASH server can trigger this by serving a live manifest with a decreasing startNumber across a manifest refresh.

Affected products

• Ffmpeg Ffmpeg

Published 2026-08-19. Last modified 2026-08-31.