CVE 2019-9588
There is an Invalid memory access in gAtomicIncrement() located at GMutex.h in Xpdf 4.01. It can be triggered by sending a crafted pdf file to (for example) the pdftops binary. It allows an attacker to cause Denial of Service (Segmentation fault) or possibly have unspecified other impact.
See the
CVE page on Mitre.org
for more details.