FFmpeg <=4.3 contains a buffer overflow vulnerability in libavcodec through a crafted file that may lead to remote code execution.
https://trac.ffmpeg.org/ticket/8863
https://trac.ffmpeg.org/ticket/8845
https://security.gentoo.org/glsa/202105-24
http://git.videolan.org/?p=ffmpeg.git%3Ba=commitdiff%3Bh=d6f293353c94c7ce200f6e0975ae3de49787f91f