KB5064489: Fix for Azure Virtual Machines with Trusted Launch disabled

July 13, 2025— KB5064489 (OS Build 26100.4656) Out-of-band

Improvements
This Out-of-band (OOB) update includes quality improvements. This update is cumulative and includes security fixes and improvements from the July 8, 2025, security update (KB5062553), in addition to the following:

• [Fix for Azure Virtual Machines with Trusted Launch disabled] This update addresses an issue that prevented some virtual machines (VMs) from starting when Virtualization-Based Security (VBS) was enabled. It affected VMs using version 8.0 (a non-default version) where VBS was offered by the host. In Azure, this applies to standard (non–Trusted Launch) General Enterprise (GE) VMs running on older VM SKUs. The problem was caused by a secure kernel initialization issue.