An issue was discovered in ImageMagick 7.0.7. The MogrifyImageList function in MagickWand/mogrify.c allows attackers to cause a denial of service (assertion failure and application exit in ReplaceImageInList) via a crafted file.
https://github.com/ImageMagick/ImageMagick/issues/802
https://lists.debian.org/debian-lts-announce/2020/08/msg00030.html