The WriteImages function in magick/constitute.c in ImageMagick before 6.9.2-4 allows remote attackers to cause a denial of service (NULL pointer dereference) via a crafted image file.
https://github.com/ImageMagick/ImageMagick/pull/34
https://github.com/ImageMagick/ImageMagick/commit/5b4bebaa91849c592a8448bc353ab25a54ff8c44
https://access.redhat.com/errata/RHSA-2016:1237
http://www.securityfocus.com/bid/91039
http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html