GraphicsMagick through 1.3.35 has a heap-based buffer overflow in ReadMNGImage in coders/png.c.
https://security.gentoo.org/glsa/202209-19
https://lists.debian.org/debian-lts-announce/2020/06/msg00004.html
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=19025
http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00012.html
http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00008.html