ImageMagick before 7.1.2-26 and 6.9.13-51 is missing a check for the allowed memory allocation...

ImageMagick before 7.1.2-26 and 6.9.13-51 is missing a check for the allowed memory allocation limit in matrix-backed operations such as -canny. An attacker can supply a crafted image that causes ImageMagick to allocate more memory than permitted by the configured policy, resulting in a denial of service.