CVE-2026-65704: Ffmpeg

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

FFmpeg through 8.1.2 contains an out-of-bounds write vulnerability that allows attackers to cause heap corruption by supplying a crafted ffconcat file processed with the -safe 0 flag. The TY demuxer's demux_audio() function decrements packet size without bounds checking, producing a negative size value that is passed to memcpy() in shorten_decode_frame(), where conversion to size_t wraps the value to near SIZE_MAX and triggers reads beyond the source allocation and writes far beyond the Shorten decoder's bitstream buffer.

Affected products

• Ffmpeg Ffmpeg: up to and including 8.1.2

Published 2026-07-23. Last modified 2026-08-07.