In ImageMagick before 6.9.9-0 and 7.x before 7.0.6-1, the ReadOneMNGImage function in coders/png.c has an out-of-bounds read with the MNG CLIP chunk. Upstream patch: https://github.com/ImageMagick/ImageMagick/commit/22e0310345499ffe906c604428f2a3a668942b05
Created ImageMagick tracking bugs for this issue: Affects: fedora-all [bug 1486807]