The MITRE CVE dictionary describes this issue as:
Poppler through 0.62 contains an out of bounds read vulnerability due to an incorrect memory access that is not mapped in its memory space, as demonstrated by pdfunite. This can result in memory corruption and denial of service. This may be exploitable when a victim opens a specially crafted PDF file.
Find out more about CVE-2018-13988 from the
MITRE CVE dictionary dictionary and
Red Hat Product Security has rated this issue as having a security impact of Low, and a future update may address this flaw.