ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to versions 7.1.2-15 and 6.9.13-40, a crafted MSL script triggers a heap-use-after-free. The operation element handler replaces and frees the image while the parser continues reading from it, leading to a UAF in ReadBlobString during further parsing. Versions 7.1.2-15 and 6.9.13-40 contain a patch.