Microsoft has started rolling out the new cumulative update KB5087420 for Windows 11 version 23H2. Released as part of the May 2026 Patch Tuesday cycle, the update upgrades PCs to OS Build 22631.7079 and includes important security fixes, reliability improvements, and SmartScreen enhancements.
The update is mandatory for supported devices because it contains security patches addressing vulnerabilities discovered over recent months.
What Is Windows 11 KB5087420?
The May 12, 2026 cumulative update is now available for Windows 11 23H2 users through Windows Update, Microsoft Update Catalog, and WSUS channels. Microsoft says the release focuses on security improvements while also bringing fixes carried over from previous preview updates.
According to Microsoft’s official release notes, the update advances Windows 11 version 23H2 to:
- OS Build: 22631.7079
- Release Date: May 12, 2026
- Update Type: Patch Tuesday security update
Key Changes and Improvements
One of the notable improvements in KB5087420 is an enhancement to Microsoft Defender SmartScreen. Microsoft says SmartScreen can now send hashes for unsigned files directly from the Windows shell, allowing newer reputation models to improve application reputation checks and security detection.
The update also includes:
- Security patches for Windows 11
- Reliability improvements
- Bug fixes from earlier preview releases
- Servicing stack enhancements for smoother future updates
Microsoft has not published a long list of user-facing features for this build, suggesting the release mainly targets system stability and protection.
Patch Tuesday Includes Security Fixes for 120 Vulnerabilities
Reports indicate that Microsoft’s May 2026 Patch Tuesday updates collectively address around 120 security vulnerabilities across Windows and related services.
This makes KB5087420 an important update for Windows 11 23H2 users, especially for enterprise and business environments where security compliance matters.
How to Install KB5087420
You can install the update by following these steps:
- Open Settings
- Go to Windows Update
- Click Check for updates
- Download and install KB5087420
- Restart your PC
The update should install automatically on most supported systems over the coming days.
Windows 11 23H2 Continues Receiving Updates
Windows 11 version 23H2 remains actively supported and continues to receive monthly cumulative updates from Microsoft. The latest release follows April’s KB5082052 update and keeps the platform secure while Microsoft continues development of newer Windows 11 versions like 24H2, 25H2, and 26H1.
Users already running Windows 11 23H2 can expect this update to arrive automatically through standard servicing channels.
Download link
You can download and manually install Windows 11 update KB5087420 by clicking here. If you need help in understanding how to install these updates manually on your PC, you can refer to our step-by-step noob-friendly tutorial.
Final Thoughts
KB5087420 may not introduce flashy new features, but it is an important security-focused update for Windows 11 23H2 users. With SmartScreen improvements, vulnerability patches, and servicing fixes, the May 2026 Patch Tuesday release helps keep Windows systems protected and stable.
For users on Windows 11 version 23H2, installing the update as soon as possible is recommended.
Official Microsoft release notes: KB5087420 Support Page
New Windows 11 Features and Improvements coming next
Microsoft just confirmed officially that “move the taskbar to the top” option is finally coming to Windows 11. It has also added a new CPU boost feature with low latency profiles for improved user experience and improvements like “Infinite Scrolling” and More to Touchpads”.
You can read about new features and improvements coming to Windows 11 Start Menu, Taskbar, and Task Manager (NPU AI tracking), refreshed run dialog in our latest coverage.
Microsoft has also delivered Major File Explorer, System Performance, and Update Improvements recently. Stay tuned to WinCentral for all latest news about Windows 11 and keep reading our full coverage here.
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