Details for this vulnerability have not been published by NIST at this point. Descriptions from software vendor advisories for this issue are provided below.
Laszlo Ersek discovered that EDK II incorrectly validated certain signed images. An attacker could possibly use this issue with a specially crafted image to cause EDK II to hang, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2019-14562)
It was discovered that EDK II incorrectly parsed signed PKCS #7 data. An attacker could use this issue to cause EDK II to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2019-14584)