Emergency Security Maintenance – Windows Hypervisor Host Nodes

Update timeline

1. identified Nov 10, 2026, 07:58 PM UTC

   Microsoft has just released security updates for several **Critical** vulnerabilities affecting Windows Server, including the Hyper-V platform our host nodes run on. To protect customer workloads, we are applying these updates to all host nodes on an emergency basis. **Start:** Immediately **Expected impact:** About 40–60 minutes per server. We’re patching host nodes in batches, so not all servers will be affected at the same time. Your server will be unreachable during maintenance. It will not be restarted, and everything running on it will continue as normal once maintenance is complete. **Recommended action:** Depending on the Windows features and services running on your server, these vulnerabilities may also affect it. We strongly recommend installing the latest Windows updates on your server as soon as possible. We’ll post an update here when all host nodes are patched. If you have any questions, please open a support ticket.

2. identified Nov 11, 2026, 03:54 AM UTC

   After extensive testing of the security patches on our host nodes, we’ve found that customer servers **will need to be restarted**. In past Windows updates, we’ve always been able to save each server’s state and restore it afterwards, and we expected the same this time. However, after this patch is applied, servers can no longer be restored from a saved state. We will begin applying the patches to our live host nodes immediately. To protect your data, we will attempt a clean shutdown of each customer server, where possible, before patching its host node. Your server will start again automatically once patching is complete. **What this means for you:** * Any unsaved work on your server will be lost. Please save your work and close important applications before maintenance. * Applications and services that aren’t set to start automatically will need to be started manually after your server comes back online. * If you prefer, you can shut down your server yourself before maintenance. **Start:** Immediately **Expected impact:** About 40–60 minutes per server. We apologize for any inconvenience this may cause. Microsoft has rated these vulnerabilities as Critical, and applying the patches promptly is essential to keeping your servers and data secure. We also strongly recommend installing the latest Windows updates on your own server as soon as possible. If you have any questions, please open a support ticket.