Microsoft has recently confirmed that its security updates released in September 2026 could cause instability in Remote Desktop Services (RDS), potentially affecting remote management capabilities across a wide array of enterprise systems.
Widespread Impact on Windows Systems
Last week, administrators globally reported encountering significant disruptions in Remote Desktop Services, which they attributed to the updates released during Microsoft’s September 2026 Patch Tuesday. This issue specifically relates to KB5124008 on Windows 11 versions 24H2 and 25H2, along with similar updates for other Windows versions.
According to Microsoft’s Windows release health dashboard, environments using RDS might initially function without issues. However, Remote Desktop Protocol (RDP) connections could fail after some time, resulting in user login failures and servers becoming stuck on the ‘Please wait for the Remote Desktop Configuration’ screen. This effectively prevents access to remote systems.
Extended Impact Beyond RDP
The repercussions of this issue extend beyond RDP alone. Microsoft has issued warnings that Microsoft Management Console (MMC), RDS Licensing Diagnoser, and File Explorer might also become unresponsive on impacted devices. Additionally, the Windows Update settings page may freeze, continuously showing a loading symbol, complicating the identification of issues and regular system management.
The problem, which Microsoft marked as ‘Mitigated’ on September 11, does not appear to stem from exploitation or a newly disclosed vulnerability. Instead, it is considered a reliability regression introduced by the update.
Potential Workarounds and Future Fixes
Administrators facing inaccessible virtual machines via RDP can temporarily restore connectivity by stopping and restarting the affected VM. However, this is a temporary measure, as the instability is likely to recur until Microsoft provides a full solution.
Organizations are advised to contact Microsoft Support for Business for immediate alternatives. It is recommended to test the September updates against RDS session hosts and other related systems before broader deployment, ensuring that an alternative management path, such as a cloud console, remains accessible.
Microsoft is currently developing a permanent fix, though a release date has yet to be announced. Given that uninstalling the security update would remove its protections, administrators should evaluate the potential risks and impacts before considering a rollback.
