In ImageMagick 7.0.7-12 Q16, a large loop vulnerability was found in the function ExtractPostscript in coders/wpg.c, which allows attackers to cause a denial of service (CPU exhaustion) via a crafted wpg image file that triggers a ReadWPGImage call.
https://usn.ubuntu.com/3681-1/
https://lists.debian.org/debian-lts-announce/2020/09/msg00007.html
https://lists.debian.org/debian-lts-announce/2019/05/msg00015.html
https://lists.debian.org/debian-lts-announce/2018/01/msg00000.html