In Artifex MuPDF 1.12.0 and earlier, multiple heap use after free bugs in the PDF parser could allow an attacker to execute arbitrary code, read memory, or cause a denial of service via a crafted file.
pdf/pdf-write.c in Artifex MuPDF before 1.12.0 mishandles certain length changes when a repair operation occurs during a clean operation, which allows remote attackers to cause a denial of service (buffer overflow and application crash) or possibly have unspecified other impact via a crafted PDF document.