Thought Leadership
The September updates for Windows Server 2019, 2022, and 2025 cause Remote Desktop Services to fail after a period of time.
Following the installation of the September security updates from this year’s Patch Tuesday, Windows administrators report outages of Remote Desktop Services (RDS) on Windows Server 2019, 2022, and 2025. Affected are the cumulative updates KB5122876 (Server 2019), KB5122882 (Server 2022), and KB5122871 (Server 2025). As a result, users can no longer connect via Remote Desktop; in some cases, a hard reboot of the server is required to restore functionality. The portal BleepingComputer was first to report on the issue.
Windows: Outage usually occurs with a delay
According to numerous reports on the Reddit forum r/sysadmin, affected RDS servers initially function normally for several hours before connections begin to fail. Existing Remote Desktop sessions can then sometimes no longer be properly disconnected or logged off, while new connection attempts hang during session establishment and ultimately fail. BleepingComputer itself also received reader reports about comparable issues on classic terminal servers.
One administrator reported that all of his terminal servers failed within a single day, with a hard reboot being the only remedy. Another administrator described that Remote Desktop Services initially worked normally after installation, but crashed starting with the first user log-off, leaving no one able to log in afterward. A simple restart of the server did not resolve the issue in this case.
Possible cause: Deadlock between RDP and session management
An administrator who investigated the issue more closely on a Server 2022 reported in the same Reddit forum that the RDP service stopped responding as soon as users attempted to log off; his own error analysis pointed to a mutual lock (deadlock) between the Remote Desktop service and the Local Session Manager, specifically at RDPSERVERBASE!WDLIB_Close, for which no timeout appears to be set. Microsoft has not yet confirmed this explanation.
No official statement from Microsoft
Administrators who uninstalled the September updates report that this restores Remote Desktop functionality. However, uninstalling them also removes the security fixes included in the updates. BleepingComputer asked Microsoft for a statement on whether the company is aware of the reported issues and whether a fix or workaround is available; as of the publication of the report, no response had been received. The issue is also not yet listed as a known error in the official support notes for the affected updates.
(Editorial Team)
