In FFmpeg 4.0.1, due to a missing check for negative values of the mquant variable, the vc1_put_blocks_clamped function in libavcodec/vc1_block.c may trigger an out-of-array access while converting a crafted AVI file to MPEG4, leading to an information disclosure or a denial of service.
Severity
CVSS 3.0
8.1 high
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
EPSS
1.4% chance of exploitation in the next 30 days; higher than 72% of CVEs (scores of 2026-10-31)