Microsoft has released an emergency update to fix a bug that prevents Azure virtual machines from launching when the Trusted Launch setting is disabled and Virtualization-Based Security (VBS) is enabled. On Sunday, Microsoft released the KB5064489 out-of-band update for Windows 11 24H2 and Windows Server 2025, which fixes the kernel initialization issue that prevented the VMs from launching. "This update addresses an issue that prevented some virtual machines (VMs) from starting when Virtualization-Based Security (VBS) was enabled," explains Microsoft. Microsoft has also updated the Windows Server 2025 VM images to include the newer cumulative update that fixes this bug. Trusted Launch is an Azure feature that uses Secure Boot and a virtual Trusted Platform Module (vTPM) to protect virtual machines against bootkits and other low-level threats. The bug impacted Windows Server 2025 and Windows 11 24H2 and was introduced during the July Patch Tuesday security updates. If you are impacted, Microsoft recommends installing this out-of-band update instead of the July 8th KB5062553 Patch Tuesday update. Lawrence Abrams Lawrence Abrams is the owner and Editor in Chief of BleepingComputer.com. Lawrence's area of expertise includes Windows, malware removal, and computer forensics.
This Cyber News was published on www.bleepingcomputer.com. Publication date: Tue, 15 Jul 2025 18:50:17 +0000