Windows updates since October 2026 slow SQL Server linked queries
Original title: Microsoft: Recent Windows updates cause SQL Server performance issues
OLE DB connections to Oracle and PostgreSQL can stay open; an out-of-band Windows fix is due within days.
Microsoft confirmed that Windows updates released since the October 2026 Patch Tuesday leave SQL Server linked-server connections open after OLE DB queries finish. Open connections to external databases accumulate and degrade performance. Windows 10, Windows 11, and Windows Server 2012 and later are affected. Administrators can close leftover connections or restart SQL Server temporarily. Microsoft Support for Business can provide a mitigation until an out-of-band update ships.
Unconfirmed: Microsoft has not named the out-of-band update build or an exact release date beyond the next few days.
- Oracle and PostgreSQL linked-server connections are among those known to be affected.
- Restarting SQL Server can kill active queries and the problem can return.
- A separate September issue can crash SQL Server on Windows Server 2025 when LPIM is enabled.
- November 2026 updates may fail on Windows 11 with October preview installed, showing 0x80070306, 0x800f0989, or 0x800f0993.
Impact: accumulating open connections degrade SQL Server performance
| Product | Affected |
|---|---|
| Microsoft Windows | Windows 10, Windows 11, and Windows Server 2012 and later with updates since the October 2026 Patch Tuesday |
| Microsoft SQL Server | linked server queries using OLE DB providers |
- 1.Contact Microsoft Support for Business for the interim mitigation.
- 2.Manually close leftover external connections or restart the SQL service only as a temporary measure.
- Vendors
- Microsoft
From the original article
2 min read at bleepingcomputer.com
Microsoft has confirmed that Windows updates released since the October 2026 Patch Tuesday are causing SQL Server performance and stability issues. [...]
By Sergiu Gatlan · bleepingcomputer.com
A short excerpt; the article and its images belong to the publisher. Summary, key facts and assessment above are AI-written from the article and can be wrong.