KB5126653

Microsoft has released cumulative update KB5126653 for Windows 11, version 23H2 (2023 Update), as part of the October 2026 Patch Tuesday. Build 22631.7652. The update includes quality improvements only, and no new system features are introduced. Microsoft fixed 1411 security issues, including three zero-day vulnerabilities.

• Security. This update contains various security improvements to internal OS functionality for October 2026.
• Secure Boot. The rollout of updated Secure Boot certificates continues. Current high-confidence data is used to identify devices that are ready to receive the new certificates automatically. Distribution through Windows Update continues on supported devices.
• File History. Fixed an issue where File History might fail to back up or restore files on an external drive or network location. Affected devices might incorrectly display the message Reconnect your drive, even though a compatible backup drive was connected and working properly.
• Date and time. Added support for permanent daylight saving time in British Columbia and Alberta starting in November 2026, as well as a new time zone (UTC-05:00) Manitoba.
• Storage Spaces. Fixed an issue with Storage Spaces Direct virtual disks that use storage tiers. After installing certain security updates, some virtual disks might fail to come online, making dependent cluster workloads unavailable.
• ReFS security. Added auditing and additional policy-based controls for ReFS volumes on external drives. Auditing is enabled by default, while enforcement is disabled, so administrators can evaluate the upcoming security hardening changes and prepare for them.

Cumulative update KB5126653 is installed automatically on PCs through Windows Update for Enterprise and Education editions. To check, go to Settings > Windows Update and click Check for updates.

Along with the cumulative update, Microsoft released Windows 11 dynamic updates for version 23H2 on October 13: Safe OS Dynamic Update KB5126666 updates the WinRE recovery environment to version 10.0.22621.7649, and Setup Dynamic Update KB5127363 updates the setup files. Both packages are installed automatically through Windows Update, and manual installation is mostly needed when preparing installation images.

Please note: support for Windows 11, version 23H2 in the Home and Pro editions ended on November 11, 2025. After this date, the system no longer automatically receives monthly security updates. Microsoft recommends upgrading to Windows 11, version 25H2.

The last 10 Windows updates: