A security feature bypass vulnerability exists when Windows Secure Kernel Mode fails to properly handle objects in memory.To exploit the vulnerability, a locally-authenticated attacker could attempt to run a specially crafted application on a targeted system, aka 'Windows Secure Kernel Mode Security Feature Bypass Vulnerability'.
https://www.tenable.com/blog/tenable-roundup-for-microsofts-june-2019-patch-tuesday
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1044