In the March 2026 Patch Tuesday update, Microsoft addressed 79 vulnerabilities, including two publicly disclosed zero-day flaws and three critical issues. Updates KB5079473 and KB5078883 were released for Windows 11, while Windows 10 received KB5078885.

Main Changes and Fixed Vulnerabilities

The March 10, 2026 update includes fixes for 79 vulnerabilities, among them two publicly disclosed zero-day issues: CVE-2026-21262 in SQL Server and CVE-2026-26127 in .NET. Additionally, two remote code execution vulnerabilities in Microsoft Office were resolved, which could be triggered via the preview pane.

Updates for Windows 11 and Windows 10

• Windows 11 (versions 25H2 and 24H2): Update KB5079473 raised the build numbers to 26200.8037 and 26100.8037, respectively.
• Windows 11 (version 23H2): Update KB5078883 upgraded the system to build 22631.6783.
• Windows 10 (versions 22H2 and 21H2): Update KB5078885 increased the build numbers to 19045.7058 and 19044.7058.

Key Improvements and Fixes

Windows 11 (KB5079473)

• Includes the latest security fixes and changes from last month's preview release.
• Expanded application of Secure Boot certificates.
• Improved search reliability in File Explorer across multiple drives and the "This PC" section.
• Enhanced handling of COM permission policies in Windows Defender Application Control.
• Added a clearer trust warning in Windows System Image Manager.
• No known issues have been identified with this update so far.

Windows 11 (KB5078883)

• Security issues fixed and February quality improvements added.
• Introduced new Secure Boot certificates and two new PowerShell options related to Secure Boot.
• Improved File History reliability for certain character sets.
• Enhanced GPU stability during shutdown and under heavy graphics loads.
• Added a similar trust warning in Windows System Image Manager.
• No known issues with this update.

Windows 10 (KB5078885)

• Includes March security fixes and a small set of quality improvements.
• Added a trust source warning when selecting catalog files in Windows System Image Manager.
• Fixed File History backup errors for some Chinese and special characters.
• Improved GPU stability.
• Expanded use of new Secure Boot certificates for compatible devices.
• No issues have been detected with this update.

Additional Information

This month’s update primarily focuses on vulnerability remediation rather than introducing new features. In addition to the two publicly disclosed zero-day vulnerabilities, two Office bugs that could be exploited via the preview pane were fixed, as well as an Excel information disclosure issue that could potentially lead to data leaks through Copilot Agent mode.

Windows 10 Support Details

The Windows 10 update was released after mainstream support for the system ended on October 14, 2025. While computers can continue to operate, standard technical support, feature updates, and security updates are no longer provided, except through the Extended Security Updates program. Therefore, the March security package for Windows 10 is especially important for systems that will continue to be serviced after official support ends.