coders/pnm.c in ImageMagick 6.9.0-1 Beta and earlier allows remote attackers to cause a denial of service (crash) via a crafted png file.
http://www.openwall.com/lists/oss-security/2016/06/02/13
http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=26682