Science & Tech · Big Tech & Internet · 1 hr ago
Windows updates cause SQL Server performance and stability problems
Microsoft says Windows updates released since October’s Patch Tuesday are affecting SQL Server on Windows client and server systems.
The bug affects linked server queries that use OLE DB providers to connect SQL Server to external databases, including Oracle and PostgreSQL.
Some queries leave database connections open after they finish, and the connections build up over time.
This can reduce server performance and cause stability problems for organizations that rely on these systems.
Administrators can close lingering connections or restart the SQL service, but these steps may interrupt active queries and the problem can return.
Microsoft plans to release an out-of-band update in the coming days and says administrators can contact Microsoft Support for Business for a temporary mitigation.
Microsoft says Windows updates released since October 2026 are causing SQL Server performance and stability problems.
The issue affects linked server queries that use OLE DB providers to connect to external databases, including Oracle and PostgreSQL.
Connections can remain open after queries finish and accumulate, degrading performance over time.
The problem affects Windows client and server systems, with Windows 11 version 26H2 excluded according to The Register.
Microsoft says it plans to release an out-of-band update within the next few days.
- Who
- Microsoft and administrators of affected SQL Server systems.
- What
- Windows updates have caused linked server queries to leave connections open, leading to performance and stability problems.
- When
- Since the October 2026 Patch Tuesday; The Register identifies the October 13 update as KB5126646.
- Where
- Windows 10 and Windows 11 client systems, and Windows Server systems. The Register says Windows 11 version 26H2 is not affected.
- Why
- A bug causes connections used by SQL Server linked server queries to external databases to accumulate instead of closing.
This story does not have two clearly opposing sides.
The Register says the update KB5126646 was followed by linked server connections remaining open.
Microsoft described the issue in a Windows release health dashboard update, according to BleepingComputer.
BleepingComputer and The Register reported Microsoft's confirmation of the SQL Server problems.
Microsoft plans to release an out-of-band Windows update to fix the issue.
- Affected queries
- SQL Server linked server queries using OLE DB providers
- Known affected databases
- Oracle and PostgreSQL
- Client systems
- Windows 10 and Windows 11
- Server systems
- Windows Server 2012 and later
- Temporary measures
- Manually close idle connections or restart the SQL service
2 sources
What people are saying
This issue affects SQL Server linked server queries that use OLE DB providers to connect to external databases. Oracle and PostgreSQL connections are among those known to be affected.
In affected environments, administrators might observe an increasing number of open connections to external databases, even when the associated SQL Server linked server queries are no longer running.