FFmpeg through 9.0.2 contains a denial of service vulnerability in libavcodec/vorbis_parser.c that re-parses invalid extradata for every packet when valid_extradata remains false. Attackers can supply crafted Ogg or Matroska Vorbis streams with large invalid extradata and many packets to exhaust CPU during demuxing or probing.
https://github.com/FFmpeg/FFmpeg/commit/90f5e61a1da2dcc0050169af8ca593530f26071b
https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/vorbis_parser.c#L312
https://github.com/FFmpeg/FFmpeg
Published: 2026-11-09
Updated: 2026-11-10
Base Score: 4.9
Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:C
Severity: Medium
Base Score: 5.5
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Severity: Medium
Base Score: 6.8
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Severity: Medium
EPSS: 0.00165