What's new in KB5087420 (Windows 11 build 22631.7079)
- Windows 11 version 23H2
- Build 22631.7079
Maya Reyes3 min readQuick answer
KB5087420 is a mandatory security update released on May 12, 2026, for Windows 11 version 23H2. Installing this update advances your operating system to OS Build 22631.7079. It brings regular monthly security improvements and system refinements, downloadable via Windows Update or the Microsoft Update Catalog.
Microsoft released update KB5087420 on May 12, 2026, for devices running Windows 11 version 23H2. Installing this cumulative update bumps the system build number to OS Build 22631.7079. As a standard Patch Tuesday update, this release is mandatory for home and small business users and focuses on delivering essential security patches, background maintenance improvements, and system updates to keep your computer protected.
This update specifically targets PCs running Windows 11 version 23H2. It replaces the previous cumulative update KB5082052 (OS Build 22631.6936) released on April 14, 2026, and sets the foundation before the subsequent monthly release KB5093998 (OS Build 22631.7219) on June 9, 2026. Because KB5087420 is a security-focused cumulative update, Windows Update will automatically download and prompt you to restart your machine to complete the installation process.
Highlights
- Windows 11 version 23H2 OS build increment: Updates devices running Windows 11 version 23H2 from OS Build 22631.6936 to OS Build 22631.7079.
- Official release timing: Published on May 12, 2026, as part of Microsoft's regular monthly Patch Tuesday security update cycle.
- Cumulative update package: Consolidates security fixes, operating system patches, and previous quality improvements into a single package for version 23H2.
- Coordinated release across versions: Delivered alongside May 12, 2026 security updates for other supported Windows 11 releases, including KB5089548 for version 26H1 (OS Build 28000.2113) and KB5089549 for versions 24H2 and 25H2 (OS Builds 26100.8457 and 26200.8457).
- Servicing stack improvements: Includes underlying updates to the Windows servicing stack to ensure seamless updates and reliable installation of future cumulative releases on Windows 11 23H2 devices.
Known issues
Microsoft reports no known issues for this update.
Should you install it?
KB5087420 is a mandatory security update for Windows 11 version 23H2. Because it contains crucial security protections and cumulative quality fixes released on May 12, 2026, all users running version 23H2 should allow the update to install. Leaving your device without the latest monthly cumulative update can leave your computer vulnerable to security risks.
Most computers will download KB5087420 automatically during your scheduled active hours. If you are currently working on important projects or require uninterrupted system uptime, you can temporarily pause updates through your Windows Update settings menu to prevent an unexpected computer restart. Once your work is finished, you should resume updates and restart your computer to apply OS Build 22631.7079.
How to get it
Illustration: the Troubleshoot > Other troubleshooters page under Settings > System
You can install KB5087420 using Windows Update inside your system settings, or by downloading the standalone installer directly from the Microsoft Update Catalog.
To update using Windows Update:
- Open the Start menu and select Settings, or press the Windows key + I on your keyboard.
- In the left sidebar of the Settings window, click on Windows Update.
- Click the Check for updates button on the right panel.
- Allow Windows Update to scan for available packages. When KB5087420 appears in the list, click Download and install.
- Wait for the download and installation phases to complete, then click Restart now when prompted to update your system to OS Build 22631.7079.
To update using the Microsoft Update Catalog:
- Open your web browser and go to the Microsoft Update Catalog website.
- In the search box located at the top right, type KB5087420 and click Search.
- Locate the update package corresponding to your processor architecture (x64 or ARM64) for Windows 11 version 23H2.
- Click the Download button next to the matching package, and a popup window will open.
- Click the provided download link to save the .msu file onto your device.
- Double-click the downloaded .msu file to open the Windows Update Standalone Installer, follow the on-screen prompts, and restart your computer when finished.
If the installation gets stuck or fails to complete, you can run the built-in Windows Update troubleshooter by navigating to Settings > System > Troubleshoot > Other troubleshooters and running the Windows Update tool.
Sources
Frequently asked questions
What OS build does KB5087420 update Windows 11 23H2 to?
KB5087420 updates Windows 11 version 23H2 to OS Build 22631.7079.
Is KB5087420 an optional update?
No, KB5087420 is a mandatory Patch Tuesday security update released on May 12, 2026. Windows Update will download and install it automatically unless updates are paused.
How do I fix installation issues with KB5087420?
If KB5087420 fails to install, you can run the Windows Update troubleshooter under System > Troubleshoot in Settings, or download the standalone .msu package from the Microsoft Update Catalog.
Checked against Microsoft's release notes on ; re-checked when a new build ships.
Covers Windows 11 update releases and the problems that follow them. Tracks Microsoft's release-health notes daily and flags known issues the same day they appear.
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