A Use After Free vulnerability exists in Artifex Software, Inc. MuPDF library 1.17.0-rc1 and earlier when a valid page was followed by a page with invalid pixmap dimensions, causing bander - a static - to point to previously freed memory instead of a newband_writer.
https://bugs.ghostscript.com/show_bug.cgi?id=702253
http://git.ghostscript.com/?p=mupdf.git%3Bh=96751b25462f83d6e16a9afaf8980b0c3f979c8b