coders/rle.c in ImageMagick 7.0.5-4 has an "outside the range of representable values of type unsigned char" undefined behavior issue, which might allow remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted image.
https://blogs.gentoo.org/ago/2017/04/02/imagemagick-undefined-behavior-in-codersrle-c/