The h264_slice_header_init function in libavcodec/h264_slice.c in FFmpeg before 2.8.3 does not validate the relationship between the number of threads and the number of slices, which allows remote attackers to cause a denial of service (out-of-bounds array access) or possibly have unspecified other impact via crafted H.264 data.
Severity
CVSS 3.0
8.3 high
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L
EPSS
1.9% chance of exploitation in the next 30 days; higher than 79% of CVEs (scores of 2026-10-31)