This cumulative update for Windows Server 2022 (KB5120242), 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.
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. For more information, see Windows Secure Boot certificate expiration and CA updates.
Improvements
This security update contains fixes and quality improvements from KB5099540 (released July 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.
- [Secure Boot] This update includes additional high confidence device targeting data, increasing coverage of devices eligible to automatically receive new Secure Boot certificates. Certificate deployment via Windows updates continues across supported PCs and non-managed business devices in the coming months.
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 August 2026 Security Updates.
Windows Server 2022 servicing stack update (KB5120241) - 20348.5480
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
Windows Server Update Services (WSUS) does not display error details
After installing KB5070884 or later updates, Windows Server Update Services (WSUS) does not display synchronization error details within its error reporting. This functionality is temporarily removed to address the Remote Code Execution Vulnerability, CVE-2025-59287.
How to get this update
Before you install this update
Microsoft now 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.
Prerequisite for offline OS image servicing:
Make sure that your image includes KB5030216 (09/12/2023) or a later LCU. If not, install it on your offline media before you install the latest update. This LCU updates the SSU version to 20348.1960. That is the minimum SSU version you must have to prevent error 0x800f0823 (CBS_E_NEW_SERVICING_STACK_REQUIRED).
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 |
|---|---|
| ✅ | 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 KB5120242.
For a list of the files provided in the servicing stack update, download the file information for the SSU KB5120241 - version 20348.5480.