GraphicsMagick 1.3.26 has a NULL pointer dereference in the WriteMAPImage() function in coders/map.c when processing a non-colormapped image, a different vulnerability than CVE-2017-11638.
hg.code.sf.net/p/graphicsmagick/code/rev/29550606d8b9
www.securityfocus.com/bid/100395
lists.debian.org/debian-lts-announce/2018/08/msg00002.html
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PF62B5PJA2JDUOCKJGUQO3SPL74BEYSV/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WHIKB4TP6KBJWT2UIPWL5MWMG5QXKGEJ/
usn.ubuntu.com/4222-1/
www.debian.org/security/2018/dsa-4321