Microsoft issues emergency updates for Remote Desktop disruptions after September patches

Microsoft has published out-of-band Windows updates to address Remote Desktop Services (RDS) failures linked to its September 2026 security updates. The issue affected some Windows client and server systems, with administrators reporting failed Remote Desktop Protocol connections, sign-in problems, and servers becoming unresponsive.

Microsoft had acknowledged the reports earlier and offered temporary Group Policy-based workarounds while preparing permanent fixes. Some organizations also found that removing the September cumulative updates restored Remote Desktop functionality, although doing so also withdrew the security protections delivered in those releases.

Updates released for affected platforms

The emergency patches released September 14 include updates for several supported versions of Windows:

• Windows 10 21H2 and 22H2: KB5129236
• Windows 11 24H2 and 25H2: KB5129195
• Windows 11 26H1: KB5129194
• Windows Server 2019: KB5129238
• Windows Server 2022: KB5129237
• Windows Server 2025: KB5129235

On impacted systems, the underlying problem could also affect administrative and shell components, including Microsoft Management Console, RDS Licensing Diagnoser, File Explorer, and the Windows Update interface.

Microsoft said the Windows Server fixes address problems introduced by September updates KB5122871 for Windows Server 2025 and KB5122882 for Windows Server 2022. Availability differs by platform: the Windows 11 26H1 package is offered through Windows Update, Windows Update for Business, WSUS, and the Microsoft Update Catalog, while the server packages are available from the Update Catalog.

Additional Hyper-V and audio corrections

The Windows 11 emergency releases also resolve an issue involving Hyper-V workloads managed through Host Compute Service. In affected configurations, folders shared from a Windows host to a Linux virtual machine through Plan9 could be unavailable or fail to appear in the guest.

Microsoft additionally corrected a fault affecting certain USB Audio Class 1.0 devices in multichannel modes, such as eight-channel or 3D audio. The company said a separate USB audio issue remains unresolved: some affected devices may fail to start, provide no sound, show Code 10 errors in Device Manager, or have unresponsive volume and sound controls. Microsoft said it is continuing work on a fix for those remaining symptoms.