Microsoft Confirms Windows Updates Are Breaking SQL Server Connections

Microsoft has confirmed that Windows updates released since October 2026 Patch Tuesday are causing performance and stability issues in SQL Server.

The bug prevents certain database connections from closing after queries finish, causing open connections to accumulate and slowing down affected servers.

Microsoft is preparing an emergency out-of-band (OOB) Windows update to address the problem.

Windows updates cause SQL Server connection problems

According to Microsoft’s Windows release health dashboard, the issue affects SQL Server linked server queries that use OLE DB providers to connect to external databases, including Oracle and PostgreSQL.

Normally, these connections close after queries finish. However, affected systems keep connections open, causing their number to increase over time.

As connections accumulate, organizations may experience slower SQL Server performance, excessive open database connections, and server stability problems.

Microsoft confirms that the issue affects Windows 10, Windows 11, and Windows Server 2012 and later versions.

Microsoft provides temporary workarounds while preparing a fix

Administrators can temporarily improve performance by manually closing affected database connections or restarting the SQL Server service.

However, both actions can interrupt active queries, and the connection problem may return as new queries run.

Microsoft also recommends that affected organizations contact Microsoft Support for Business to request additional mitigation.

The company plans to release an emergency out-of-band Windows update to permanently resolve the issue in the coming days. However, Microsoft has not confirmed an exact release date.

Other Windows update problems reported in November

The SQL Server issue comes alongside several other problems affecting recent Windows updates.

Microsoft recently warned that Windows 11 KB5132061 could break older PowerShell scripts because of stricter script-signing validation.

The company also announced plans to remove 10 more eMudhra certificates from Windows 11 and Microsoft Edge on November 16.

Separately, Microsoft acknowledged KB5132061 installation failures and started rolling out an automatic fix for affected devices.

For now, organizations experiencing SQL Server connection problems can use the temporary workarounds while Microsoft prepares the permanent update.

Via Bleeping Computer