This cumulative update for Windows 11, version 23H2 (KB5126653), includes the latest security fixes and improvements, along with non-security updates from last month’s optional preview release. Visit the Windows release health dashboard for the latest status on this release.
Announcements and messages
This section provides key notifications related to this release, including announcements, change logs, and end-of-support notices.
Important
Windows 11, version 23H2 Enterprise and Education will reach end of updates on November 10, 2026. The November 2026 Windows security update will be the last update available for these editions. After this date, devices running these editions will no longer receive monthly security updates containing protections from the latest security threats. To stay protected and up to date, we recommend you upgrade to the latest version of Windows 11.
Windows Secure Boot certificate expiration
Secure Boot certificate updates remain in progress as Microsoft transitions devices from certificates that began expiring in 2026 to newer certificates. Devices that have not yet received the newer certificates can continue to start and receive standard Windows updates. Microsoft will continue delivering the newer Secure Boot certificates to eligible devices through Windows Update.
Improvements
This update addresses security issues for your Windows operating system.
Important
Use EKB KB5027397 to update to Windows 11, version 23H2.
This security update contains fixes and quality improvements from the Windows security update KB5122880 (released September 8, 2026) and from the out-of-band update KB5129242 (released September 14, 2026). The following summary outlines key issues addressed by this update. Also, included are available new features. The bold text within the brackets indicates the item or area of the change.
[Security updates] This update provides security improvements. For more information about the security vulnerabilities resolved by this update, see the Security Update Guide.
[Secure Boot] This update continues the deployment of updated Secure Boot certificates using the latest high-confidence targeting data to identify eligible devices that are ready to automatically receive the new certificates. Deployment through Windows Update remains ongoing across supported devices.
[Date and Time]
This update enables permanent Daylight Savings Time (DST) support for British Columbia and Alberta starting in November 2026.
This update introduces the new time zone Manitoba Standard Time "(UTC-5:00) Manitoba".
[File History (known issue)] Fixed: This update addresses an issue where File History might fail to back up or restore files to an external drive or network location. Affected devices might incorrectly display a “Reconnect your drive” message even when a compatible backup drive is connected and working properly.
[ReFS security] This update adds auditing and optional policy controls for ReFS volumes on externally attached storage devices. Auditing is enabled by default, while enforcement controls remain disabled by default to give administrators time to evaluate and prepare for future security hardening changes. To learn more, see KB5130741.
[Storage Spaces] This update fixes an issue that affects tiered Storage Spaces Direct virtual disks. Some virtual disks might fail to come online after installing certain security updates, making dependent clustered workloads unavailable.
If you've already installed previous updates, your device will download and install only the new updates included in this package.
Known issues in this update
Microsoft is not currently aware of any issues with this update.
Windows 11 servicing stack update (KB5126652) - 22621.7641
This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. Servicing stack updates (SSU) ensure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates. To learn more about SSUs, see Servicing stack updates.
How to get this update
Deployment
If you deploy dynamic updates such as this update to an existing Windows image, ensure the boot.stl file is included as part of the installation media. Failure to include the file might prevent devices from successfully starting from the installation media and can result in error code 0xc0430001.
Note
The boot.stl file is used during Secure Boot validation and must match the Windows version and architecture of the image you are updating.
To ensure the boot.stl file is included as part of the installation media, do one of the following:
- Use the Update WinPE script to update an existing Windows image. (Recommended)
- Manually copy the boot.stl file from the device Windows\Boot\EFI folder to the corresponding folder on your installation media before deploying the update.
For information about how to apply Dynamic Update packages to existing Windows images, see Update Windows installation media with Dynamic Update.
Install this update
To install this update, use one of the following Windows and Microsoft release channels.
| Available | Next Step |
|---|---|
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This update downloads and installs automatically from Windows Update and Microsoft Update. |
File information
For a list of the files provided in this update, download the file information for cumulative update KB5126653.
For a list of the files provided in the servicing stack update, download the file information for SSU KB5126652 - versions 22621.7641.
Related topics
Microsoft Store for Business and Education with Configuration Manager