Windows 10 Receives KB5099539 Security Update with Bug Fixes and Secure Boot Enhancements

Microsoft has released KB5099539, a new security update for Windows 10 version 22H2, Windows 10 Enterprise LTSC 2021, and Windows 10 IoT Enterprise LTSC 2021. While the update does not introduce any new features, it delivers the latest security patches, resolves several bugs, and continues the rollout of updated Secure Boot certificates.

Eligible devices enrolled in Microsoft’s Extended Security Updates (ESU) program will receive the update automatically through Windows Update.

Security Patches Bring Windows 10 to Build 19045.7548

KB5099539 focuses on protecting Windows 10 systems against recently discovered security vulnerabilities.

After installation, supported devices are updated to Windows 10 Build 19045.7548, ensuring they remain protected with Microsoft’s latest security fixes.

Unlike the latest Windows 11 updates, KB5099539 is strictly a maintenance and security release with no new user-facing features.

Several Windows 10 Bugs Resolved

In addition to security improvements, Microsoft has addressed several issues affecting system reliability.

The update fixes:

• A File Explorer bug that caused OneDrive shortcuts to stop working when File Explorer was launched with administrator privileges.
• An incorrect error message that could appear when deleting files.
• Problems affecting certain keyboard shortcuts.

These fixes improve the stability and usability of Windows 10 without changing its overall functionality.

Secure Boot Certificate Rollout Continues

KB5099539 also continues Microsoft’s deployment of new Secure Boot certificates.

The previous certificates used by many Windows devices began expiring in June 2026, prompting Microsoft to distribute updated certificates through Windows Update.

According to Microsoft, devices that have not yet received the new certificates will continue to boot normally and install standard Windows updates. The rollout of the updated certificates will continue gradually over the coming months.

Available Only for ESU-Enrolled Devices

The update is available only to Windows 10 devices enrolled in the Extended Security Updates (ESU) program.

Microsoft recently extended the Windows 10 ESU program through October 12, 2027, allowing eligible systems to continue receiving critical security updates after the operating system’s official end of support.

For participating users and organizations, KB5099539 installs automatically via Windows Update, ensuring Windows 10 systems remain protected with the latest security and stability improvements.