April 12, 2022—KB5012591 (OS Build 18363.2212)

EXPIRATION NOTICEAs of 9/12/2023, KB5012591 is only available from Windows Update. This update is no longer available from the Microsoft Update Catalog, or other release channels. We recommend that you update your devices to the latest security quality update.

3/15/22 **IMPORTANT **Windows 10, version 1909, all editions, will reach end of service on May 10, 2022. After May 10, 2022, devices running Windows 10, version 1909 will no longer receive monthly security and quality updates that contain protection from the latest security threats. To continue receiving security and quality updates, Microsoft recommends updating to the latest version of Windows 10 or Windows 11.

11/19/20
For information about Windows update terminology, see the article about the types of Windows updates and the monthly quality update types. For an overview of Windows 10, version 1909, see its update history page.NoteFollow @WindowsUpdate to find out when new content is published to the Windows release health dashboard.

Highlights

• Updates security for your Windows operating system.

Improvements

This security update includes quality improvements. Key changes include:

• This update contains miscellaneous security improvements to internal OS functionality. No additional issues were documented for this release.
  If you installed earlier updates, only the new updates contained in this package will be downloaded and installed on your device. For more information about security vulnerabilities, please refer to the new Security Update Guide website and the April 2022 Security Updates.

Windows 10 servicing stack update - 18363.2150

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.

Known issues in this update

How to get this update

If you want to remove the LCUTo remove the LCU after installing the combined SSU and LCU package, use the DISM/Remove-Package command line option with the LCU package name as the argument. You can find the package name by using this command:DISM /online /get-packages.Running Windows Update Standalone Installer (wusa.exe) with the**/uninstall **switch on the combined package will not work because the combined package contains the SSU. You cannot remove the SSU from the system after installation.

File informationFor a list of the files that are provided in this update, download the file information for cumulative update 5012591. For a list of the files that are provided in the servicing stack update, download the file information for the SSU - version 18363.2150.