Microsoft: September updates cause RDS failures on Windows Server
Microsoft's September 2026 security updates cause Remote Desktop Services (RDS) failures on Windows Server 2012 and later, as well as Windows 10 and Windows 11 devices. The issue manifests as unstable RDS, failed RDP connections after several minutes, sign-in problems, and servers hanging on the Remote Desktop Configuration screen. Related tools such as MMC, RDS Licensing Diagnoser, and File Explorer may become unresponsive. Existing Remote Desktop sessions may not disconnect properly, and new connection attempts can hang or fail. Microsoft provides Group Policy-based mitigations for affected versions while working on a permanent fix. Rolling back the updates restores functionality but removes security fixes.
AI Analysis
Technical Summary
Microsoft confirmed that the September 2026 security updates cause failures in Remote Desktop Services on Windows Server 2012 and later, Windows 10, and Windows 11. The failures include unstable RDS sessions, failed or hanging RDP connections, sign-in issues, and unresponsive management tools. Affected users report servers hanging at the Remote Desktop Configuration phase and issues with session disconnection. Microsoft offers Group Policy mitigations specific to affected Windows versions and advises that restarting affected virtual machines or rolling back updates can temporarily restore RDS connectivity. A permanent fix is still in development.
Potential Impact
The impact includes disruption of Remote Desktop Services, preventing users from establishing or maintaining RDP connections. This can cause operational downtime for systems relying on remote administration and access. Related management tools may become unresponsive, complicating troubleshooting and management. Rolling back updates to restore RDS functionality removes the security protections provided by the September 2026 Patch Tuesday updates.
Mitigation Recommendations
Microsoft provides Group Policy settings for various affected Windows versions to mitigate the RDS failures caused by the September 2026 updates. Administrators can apply these Group Policies to restore RDS functionality temporarily. Restarting affected virtual machines may also restore connectivity. Rolling back the problematic updates is another option but removes important security fixes. Microsoft is working on a permanent fix. Administrators should monitor official Microsoft advisories for updates.
Microsoft: September updates cause RDS failures on Windows Server
Description
Microsoft's September 2026 security updates cause Remote Desktop Services (RDS) failures on Windows Server 2012 and later, as well as Windows 10 and Windows 11 devices. The issue manifests as unstable RDS, failed RDP connections after several minutes, sign-in problems, and servers hanging on the Remote Desktop Configuration screen. Related tools such as MMC, RDS Licensing Diagnoser, and File Explorer may become unresponsive. Existing Remote Desktop sessions may not disconnect properly, and new connection attempts can hang or fail. Microsoft provides Group Policy-based mitigations for affected versions while working on a permanent fix. Rolling back the updates restores functionality but removes security fixes.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Microsoft confirmed that the September 2026 security updates cause failures in Remote Desktop Services on Windows Server 2012 and later, Windows 10, and Windows 11. The failures include unstable RDS sessions, failed or hanging RDP connections, sign-in issues, and unresponsive management tools. Affected users report servers hanging at the Remote Desktop Configuration phase and issues with session disconnection. Microsoft offers Group Policy mitigations specific to affected Windows versions and advises that restarting affected virtual machines or rolling back updates can temporarily restore RDS connectivity. A permanent fix is still in development.
Potential Impact
The impact includes disruption of Remote Desktop Services, preventing users from establishing or maintaining RDP connections. This can cause operational downtime for systems relying on remote administration and access. Related management tools may become unresponsive, complicating troubleshooting and management. Rolling back updates to restore RDS functionality removes the security protections provided by the September 2026 Patch Tuesday updates.
Defensive Guidance
Microsoft provides Group Policy settings for various affected Windows versions to mitigate the RDS failures caused by the September 2026 updates. Administrators can apply these Group Policies to restore RDS functionality temporarily. Restarting affected virtual machines may also restore connectivity. Rolling back the problematic updates is another option but removes important security fixes. Microsoft is working on a permanent fix. Administrators should monitor official Microsoft advisories for updates.
Technical Details
- Classification
- {"confidence":0.3,"severitySource":"default","classifier":"rss-v2"}
Threat ID: 6aa7c98555bf5e2cf5e5144e
Added to database: 09/14/2026, 10:16:37 UTC
Last enriched: 09/14/2026, 10:16:45 UTC
Last updated: 09/14/2026, 13:10:36 UTC
Views: 7
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