An information disclosure vulnerability exists when Windows Hyper-V writes uninitialized memory to disk. An attacker could exploit the vulnerability by reading a file to recover kernel memory. To exploit the vulnerability, an attacker would first require access to a Hyper-V host. The security update addresses the vulnerability by ensuring Hyper-V properly initializes memory before writing it to disk.
Microsoft Windows Hyper-V CVE-2019-1254 Local Information Disclosure Vulnerability
KB4516044: Windows 10 Version 1607 and Windows Server 2016 September 2019 Security Update
KB4512578: Windows 10 Version 1809 and Windows Server 2019 September 2019 Security Update
KB4516068: Windows 10 Version 1703 September 2019 Security Update
KB4516066: Windows 10 Version 1709 September 2019 Security Update
KB4515384: Windows 10 Version 1903 September 2019 Security Update
KB4516058: Windows 10 Version 1803 September 2019 Security Update