Administrators have reported Remote Desktop Services failures several hours after installing the September 2026 cumulative updates. Before removing a patch, validate the behavior and weigh the operational impact against the security fixes it contains.
Reported symptoms
Affected terminal servers may stop disconnecting existing sessions correctly, fail when users log out, or leave new RDP connections hanging. Some reports say that only a hard reboot restores access. The source describes a possible RDS and Local Session Manager deadlock, but does not state that Microsoft has confirmed the cause.
The reports identify these packages:
- Windows Server 2019:
KB5122876 - Windows Server 2022:
KB5122882 - Windows Server 2025:
KB5122871
Practical validation
- Test the update on representative terminal-server workloads before broad deployment.
- Exercise session disconnects, user logoff, and new RDP connections over time; the issue may not appear immediately.
- Prepare an alternate administration path and a documented recovery procedure.
- Record the installed package, affected server, and symptom start time for comparison.
Why it matters
Uninstalling the update also removes that month’s security fixes. The source cites several Remote Desktop-related vulnerabilities, including a high-severity remote-code-execution issue, so the decision should reflect exposure, test results, and available mitigations.
Practical takeaway
Do not roll back every server immediately. Reproduce the failure in a controlled scope, preserve alternate access, and use any rollback as a limited, documented measure while monitoring for a corrective update or other supported resolution.