June 9, 2026—KB5093998 (OS Build 22631.7219)

This cumulative update for Windows 11, version 23H2 (KB5093998), includes the latest security fixes and improvements, along with non-security updates from last month’s optional preview release. To learn more about differences between security updates, optional non-security preview updates, out-of-band (OOB) updates, and continuous innovation, see Windows monthly updates explained. For information on Windows update terminology, see the different types of Windows software updates.

To view the latest updates about this release, visit the Windows release health dashboard or the update history page for Windows 11, version 23H2.

Tip: This month’s video is available in the Windows 11, version 25H2 and 24H2 article.

Announcements and messages

This section provides key notifications related to this release, including announcements, change logs, and end-of-support notices.

Windows Secure Boot certificate expiration

Important: Secure Boot certificates used by most Windows devices are set to expire starting in June 2026. Microsoft has been updating these certificates on consumer and non-managed business devices over the past several months. Devices that haven’t received the newer certificates will continue to start and operate normally, and standard Windows updates will continue to install. Updated certificates will continue to be delivered through Windows Update in the coming months.

Windows 11. Version 23H2 Enterprise and Education will reach end of updates on November 10, 2026. Devices running these editions will no longer receive fixes for known issues, time zone updates, technical support, or monthly security and preview 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.

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 KB5087420 (released May 12, 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.

[Secure Boot]
- With this update, Windows quality updates include additional high confidence device targeting data, increasing coverage of devices eligible to automatically receive new Secure Boot certificates. Devices receive the new certificates only after demonstrating sufficient successful update signals, maintaining a controlled and phased rollout.
- This update adds the LimitSecureBootRequiredServiceData Group Policy and mobile device management (MDM) setting under Computer Configuration > Administrative Templates > Windows Components > Secure Boot. When enabled, Windows limits the Secure Boot service data it sends by suppressing the event normally sent to Microsoft. This policy is included in the Windows Restricted Traffic Limited Functionality Baseline. For information about the policy, see Manage connections from Windows 10 and Windows 11 operating system components to Microsoft services.
[Boot manager servicing update (Known issue)] Fixed: This update addresses an issue where some devices might enter BitLocker Recovery after updating boot files on systems with certain Trusted Platform Module (TPM) validation settings, including invalid PCR7 (Platform Configuration Register 7) configurations. This might occur after installing the April 2026 security update (KB5082052).
[Country and Operator Settings Asset (COSA)] This update brings profiles up to date for certain mobile operators.
[Device management]
- This update improves connectivity for devices enrolled in both Microsoft Management Platform Configuration and Secure Lifecycle Device Management, helping devices reliably sync and renew their certificates.
- This update improves reliability for dual‑enrolled devices managed by mobile device management platforms, including the Modern Management Platform Connector. It helps devices successfully sync and renew their certificates.
[File Explorer] This update improves File Explorer search, including support for Chinese text, and UTF 8–encoded files without a byte order mark (BOM). Text now displays more clearly and consistently across search results, Content view, and tooltips.

If you've already installed previous updates, your device will download and install only the new updates included in this package.

For more information about security vulnerabilities, see the Security Update Guide and the June 2026 Security Update.

Windows 11 servicing stack update (KB5094146) - 22621.7209

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 Simplifying on-premises deployment of servicing stack updates.

Known issues in this update

Microsoft is not currently aware of any issues with this update.

How to get this update

Before you install this update

Microsoft combines the latest servicing stack update (SSU) for your operating system with the latest cumulative update (LCU). For general information about SSUs, see Servicing stack updates.

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.