A Denial of Service vulnerability exists in FFmpeg 4.2 due to a memory leak in the av_dict_set function in dict.c.
https://www.debian.org/security/2021/dsa-4990
https://trac.ffmpeg.org/ticket/8315
https://lists.debian.org/debian-lts-announce/2021/11/msg00012.html
http://git.videolan.org/?p=ffmpeg.git%3Ba=commitdiff%3Bh=6f2a3958cfac135c60b509a61a4fd39432d8f9a9