graphicsmagick is a collection of tools and libraries for many image formats.
The complete output of the issue:
# gm convert $FILE null gm: magick/pixel_cache.c:1089: const PixelPacket AcquireImagePixels(const Image , const long, const long, const unsigned long, const unsigned long, ExceptionInfo ): Assertion `image != (Image ) NULL' failed.
1.3.25, 1.3.26 and maybe past releases
This bug was discovered by Agostino Sarubbo of Gentoo.
2017-08-12: bug discovered and reported to upstream privately
2017-08-16: bug reported to the public upstream bugtracker
2017-08-29: upstream released a fix
2017-09-19: blog post about the issue
2017-09-21: CVE assigned