Microsoft Unveils Windows 10 Security Update with Secure Boot Certificate Rollout

Microsoft has released an extended security update for Windows 10 versions 22H2 and 21H2, which includes fixes for several security vulnerabilities and bugs.

The update, known as KB5120249, is mandatory as it contains the August 2026 Patch Tuesday security updates.

To install the update, users can go to Start > Settings > Update & Security > Windows Update and click on 'Check for updates.'

Alternatively, they can manually download and install the update from the Microsoft Update Catalog.

The update will bump up the OS Builds of affected systems to 19045.7663 and 19044.7663.

Among the fixes included in this update is a resolution for a File History backup issue that caused automatic backups to network shares using Server Message Block (SMB) to fail with an 'invalid credentials' error.

The update also expands the rollout of new Secure Boot certificates, which will increase coverage of devices eligible to automatically receive these certificates.