An elevation of privilege vulnerability exists in Windows when the Windows kernel-mode driver fails to properly handle objects in memory. An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and take control of an affected system. The update addresses this vulnerability by correcting how the Windows kernel-mode driver handles objects in memory.
https://www.tenable.com/blog/microsoft-s-may-2020-patch-tuesday-addresses-111-cves
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-1054
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1054
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-1054