CVE-2019-9717 (libav)

In Libav 12.3, a denial of service in the subtitle decoder allows attackers to hog the CPU via a crafted video file in Matroska format, because srt_to_ass in libavcodec/srtdec.c has a complex format argument to sscanf.
Source: NIST
CVE-2019-9717 (libav)