FFmpeg before commit 9d786e4 contains a stack buffer overflow in the MPEG-PS muxer (libavformat/mpegenc.c). When muxing input with more streams than the muxer's fixed-size stack buffer accommodates, the buffer is overflowed. A crafted input with an excessive number of streams triggers the overflow during MPEG-PS muxing.
https://www.vulncheck.com/advisories/ffmpeg-stack-buffer-overflow-in-mpeg-ps-muxer-via-mpegenc-c
https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24087
https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/9d786e4b5e9b8482651928574de33772aeee7be1
Published: 2026-08-19
Updated: 2026-08-19
Base Score: 7.2
Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C
Severity: High
Base Score: 7.8
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Severity: High
Base Score: 8.5
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Severity: High