In ImageMagick 7.0.6-6 and GraphicsMagick 1.3.26, a heap-based buffer over-read was found in the function SFWScan in coders/sfw.c, which allows attackers to cause a denial of service via a crafted file.
hg.code.sf.net/p/graphicsmagick/code/rev/1b47e0078e05
www.securityfocus.com/bid/100476
github.com/ImageMagick/ImageMagick/issues/670
lists.debian.org/debian-lts-announce/2017/11/msg00016.html
lists.debian.org/debian-lts-announce/2018/06/msg00009.html
security.gentoo.org/glsa/201711-07
usn.ubuntu.com/3681-1/
usn.ubuntu.com/4222-1/
www.debian.org/security/2017/dsa-4032
www.debian.org/security/2017/dsa-4040
www.debian.org/security/2018/dsa-4321