In GraphicsMagick 1.3.27a, there is a buffer over-read in ReadPALMImage in coders/palm.c when QuantumDepth is 8.
https://www.debian.org/security/2018/dsa-4321
https://usn.ubuntu.com/4248-1/
https://sourceforge.net/p/graphicsmagick/bugs/529/
http://hg.graphicsmagick.org/hg/GraphicsMagick?cmd=changeset%3Bnode=60932931559a