GraphicsMagick 1.3.26 has a NULL pointer dereference vulnerability in the function SVGStartElement in coders/svg.c.
https://www.debian.org/security/2018/dsa-4321
https://usn.ubuntu.com/4222-1/
https://sourceforge.net/p/graphicsmagick/bugs/435/
https://lists.debian.org/debian-lts-announce/2018/06/msg00009.html
http://hg.code.sf.net/p/graphicsmagick/code/rev/54f48ab2d52a