Updated May 27, 2025: This message was updated to include additional versions of Windows affected by this issue.
Microsoft has identified an issue where certain confidential virtual machines running on Hyper-V might intermittently stop responding or restart unexpectedly, affecting service availability and requiring manual intervention. This issue primarily affects Azure confidential VMs and is not expected to impact standard in-market Hyper-V deployments, except in rare cases involving preview or pre-production configurations.
To address this issue, out-of-band (OOB) updates have been released, May 23, 2025 for Windows Server 2022 (KB5061906) and today, May 27, 2025 for additional versions of Windows affected by this issue. This update is available exclusively via the Microsoft Update Catalog. For more information and installation instructions, refer to the appropriate KB article for your Windows version. If your organization is not affected by this issue, you do not need to install this OOB update.
If you have not yet deployed the May 2025 Windows security update and your IT environment includes devices running Hyper-V on the versions of Windows listed below, we recommend you apply this OOB update instead: