An elevation of privilege vulnerability exists when Windows AppX Deployment Service (AppXSVC) improperly handles hard links, aka 'Windows Elevation of Privilege Vulnerability'.
https://www.tenable.com/blog/tenable-roundup-for-microsofts-june-2019-patch-tuesday
https://www.tenable.com/blog/microsoft-s-july-2019-patch-tuesday-what-you-need-to-know
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1064