An information disclosure vulnerability exists when the Windows Graphics component improperly handles objects in memory. An attacker who successfully exploited this vulnerability could obtain information to further compromise the user’s system. An authenticated attacker could exploit this vulnerability by running a specially crafted application. The update addresses the vulnerability by correcting how the Windows Graphics Component handles objects in memory.
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1078