USN-5026-1: QPDF vulnerabilities
It was discovered that QPDF incorrectly handled certain malformed PDF
files. A remote attacker could use this issue to cause QPDF to consume
resources, resulting in a denial of service. This issue only affected
Ubuntu 18.04 LTS. (CVE-2018-18020)
It was discovered that QPDF incorrectly handled certain malformed PDF
files. A remote attacker could use this issue to cause QPDF to crash,
resulting in a denial of service, or possibly execute arbitrary code.
(CVE-2021-36978)
Source: USN-5026-1: QPDF vulnerabilities