CVE-2017-17915
In GraphicsMagick 1.4 snapshot-20171217 Q8, there is a heap-based buffer over-read in ReadMNGImage in coders/png.c, related to accessing one byte before testing whether a limit has been reached.
Date published : 2017-12-26
http://hg.graphicsmagick.org/hg/GraphicsMagick/rev/1721f1b7e67a