Microsoft releases Windows 10 KB5126657 extended security update

Microsoft released the Windows 10 KB5126657 extended security update, which includes this month's record-breaking October 2026 Patch Tuesday fixes and a few bug fixes and changes.

If you are running Windows 10 Enterprise LTSC or are enrolled in the ESU program, you can install this update like normal by going into Settings, clicking on Windows Update, and manually performing a 'Check for Updates.'

After installing this update, Windows 10 will be updated to build 19045.7807, and Windows 10 Enterprise LTSC 2021 will be updated to build 19044.7807.

Microsoft no longer releases new features for Windows 10, and the KB5126657 update mainly includes security updates and bug fixes.

The update also includes fixes released as part of today's record-breaking October 2026 Patch Tuesday, which fixed a massive 1,411 vulnerabilities across Microsoft's products, including one actively exploited zero-day flaw.