For Windows 10 versions 22H2 and 21H2, Microsoft has published KB5075912, an Extended Security Update (ESU) that targets OS builds 19045.6937 and 19044.6937 This article explores security update esu. . This patch fixes serious flaws and gets systems ready for the next Secure Boot certificate expiration.

Overview of the Update KB5075912, which was released on February 10, 2026, incorporates previous fixes from January updates such as KB5073724, KB5077796, and KB5078129. For improved dependability on Azure-hosted devices and certificate validation, it comes with Servicing Stack Update (SSU) KB5077456. Users should make sure the most recent SSU is installed first by using Windows Update or the Microsoft Update Catalog. Important non-security fixes address GPU stability, File Explorer folder renaming, Secure Launch shutdown issues on VSM-enabled PCs, and Chinese font compliance.

In order to prevent boot failures by June 2026, it also gradually rolls out new Secure Boot certificates based on device update history. This ESU addresses six zero-day vulnerabilities that were exploited in the wild as well as other vulnerabilities from Microsoft's February 2026 Patch Tuesday. Notable problems include privilege elevation in Remote Desktop Services and circumvention of security features in Windows Shell and MSHTML.

After installation, there are no known problems, but administrators should review the Secure Boot instructions.

CVE-2026-21510 Windows Shell Security Feature Bypass 8.8 Actively Exploited (Zero-Day) CVE ID Title CVSS Score Exploitation Status Max Severity Crucial Bypass for CVE-2026-21513 MSHTML Framework Security Feature 8.8 Critical CVE-2026-21533 Was Actively Exploited Remote Desktop Services for Windows Privilege Elevation 7.8 Critical CVE-2026-21519 Was Actively Exploited Window Manager for Desktop Privilege Elevation 7.8 Critical CVE-2026-21525 Windows Remote Access Connection Manager Denial of Service Was Actively Exploited 6.2 Critical CVE-2026-21514 Was Actively Exploited Bypassing Microsoft Word's Security Feature 7.8 Significantly Actively Exploited Particularly for ESU customers who are postponing the Windows 11 migration, apply right away. To upgrade to version 22H2, use EKB KB5015684. For health dashboard news, follow @WindowsUpdate, and for complete CVE details, consult the Security Update Guide.

This preserves boot security while guaranteeing defense against actual attacks.