Overview
- September security updates caused Remote Desktop Services to become unstable on Windows Server 2012 and later and on Windows 10 and 11, producing dropped RDP connections, sign-in failures, and servers that hang during Remote Desktop configuration.
- Microsoft initially acknowledged the problem and published per-build Group Policy mitigations that IT teams can apply to managed fleets as temporary workarounds.
- Stopping (deallocating) and restarting affected virtual machines may temporarily restore RDP connectivity and some administrators restored service by uninstalling the September updates, which removes that month's security fixes.
- On Monday, September 14, 2026, Microsoft issued out-of-band updates that fix RDS failures for multiple Windows builds and also address some Hyper-V and USB Audio Class 1.0 multichannel problems, though some USB audio issues remain unresolved.
- The regressions also include a separate Excel paste bug affecting Office 2016/2019/2021/2024 and leave administrators weighing the risk of restored access against losing security protections with no firm timeline yet for permanent fixes and with Windows Server 2012 ESU ending on October 13, 2026.