SharePoint Security Fixes Released with February 2026 PU via Microsoft Update
Important security updates for SharePoint Server are available via the February 2026 Public Update. Ensure proper preparation to avoid installation failures.
SharePoint February 2026 PU Security Updates Released
Microsoft has released the February 2026 Public Update (PU) for SharePoint Server, containing important security fixes distributed through Microsoft Update. Before applying this update, it's crucial to address a specific configuration requirement to prevent potential installation failures.
Critical: Pre-Update Configuration for September 2025 CU Users
If your SharePoint farm is currently patched with the September 2025 CU, you must remove the NT Authority\system account from the WSS_WPG and IIS_IUSRS local security groups on your SharePoint servers. Failure to do so will cause the installation of the February 2026 security fixes to fail. Refer to the following article for detailed instructions: Trending Issue: SharePoint fixes fail to install after installation of September 2025 CU.
Pre-Installation Checklist
- Verify your current SharePoint patch level.
- Apply the pre-update configuration for September 2025 CU (if applicable).
- Prepare for potential issues during the update process.
Post-Update Verification
After the update is complete, thoroughly test your SharePoint environment to ensure everything is functioning correctly. It's also recommended to review your security settings and permissions.
This update is critical for maintaining the security of your SharePoint environment. Therefore, it is highly recommended to apply it as soon as possible.
Consider also reviewing your SharePoint Governance Plan and SharePoint Security Best Practices after applying the patch.