In ImageMagick 7.x before 7.0.8-41 and 6.x before 6.9.10-41, there is a divide-by-zero vulnerability in the MeanShiftImage function. It allows an attacker to cause a denial of service by sending a crafted file.
In ImageMagick 7.0.8-40 Q16, there is a heap-based buffer over-read in the function WritePNMImage of coders/pnm.c, which allows an attacker to cause a denial of service or possibly information disclosure via a crafted image file. This is related to SetGrayscaleImage in MagickCore/quantize.c.