A heap-based Buffer Overflow vulnerability exists in FFmpeg 4.2 in filter_intra at libavfilter/vf_bwdif.c, which might lead to memory corruption and other potential consequences.
https://www.debian.org/security/2021/dsa-4990
https://trac.ffmpeg.org/ticket/8261
https://lists.debian.org/debian-lts-announce/2021/08/msg00018.html