September Windows Server Updates Cause Remote Desktop Services Failures
Summary
Admins report that September 2026 cumulative updates cause Remote Desktop Services failures on Windows Server 2019, 2022, and 2025. Rolling back restores access but removes the updates’ security fixes; Microsoft has not confirmed a cause or provided a response.
Key points
- Reports describe Remote Desktop Services failures on Windows Server 2019, 2022, and 2025 after installing September 2026 cumulative updates.
- Servers may initially work for hours before existing sessions hang or new Remote Desktop connections stall and fail.
- Some affected administrators report needing a hard reset; restarting did not resolve the problem in one account.
- Rolling back the updates reportedly restores Remote Desktop functionality, but also removes the included security fixes.
- One administrator reported debugging evidence suggesting a deadlock between Remote Desktop and the Local Session Manager; Microsoft has not confirmed this as the cause.
- The affected updates are KB5122876 for Server 2019, KB5122882 for Server 2022, and KB5122871 for Server 2025. Microsoft had not responded to BleepingComputer at publication time.
Article Details
- Event Type
- Reported failures of Remote Desktop Services following September 2026 cumulative updates for Windows Server.
- Impact
- Affected servers may stop accepting new Remote Desktop connections, while existing sessions can hang during logoff or disconnect. Some systems reportedly require a hard reset. Rolling back the updates restored functionality for reporting administrators but also removed the included security fixes. Microsoft had not confirmed the reported cause or provided a response at publication time.
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Remote Desktop ServicesSeptember 2026 cumulative updates are causing Remote Desktop Services failures on Windows Server 2019, 2022, and 2025, leaving some systems unable to accept new connections and sometimes requiring a hard reset.Windows Server 2019September 2026 cumulative updates are causing Remote Desktop Services failures on Windows Server 2019, 2022, and 2025, leaving some systems unable to accept new connections and sometimes requiring a hard reset.