In ImageMagick 7.0.7-16 Q16 x86_64 2017-12-21, there is a heap-based buffer over-read in ReadOneMNGImage in coders/png.c, related to length calculation and caused by an off-by-one error.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.007
EPSS Ranking 70.5%