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.’
Source: BleepingComputer
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.
What’s new in Windows 10 KB5126657
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.
The complete list of fixes and changes in KB5126657 is listed below:
- [Time and Date]
-
- This update enables permanent Daylight Savings Time (DST) support for British Columbia and Alberta starting in November 2026.
- This update introduces the new time zone Manitoba Standard Time “(UTC-5:00) Manitoba”.
- [ReFS security] This update adds auditing and optional policy controls for ReFS volumes on externally attached storage devices. Auditing is enabled by default, while enforcement controls remain disabled by default to give administrators time to evaluate and prepare for future security hardening changes. To learn more, see KB5130741.
- [Storage Spaces] Addresses an issue that might cause some Storage Spaces Direct virtual disks to remain offline after installing a Windows update. This issue occurs when valid tiered storage metadata is incorrectly identified as invalid during recovery, preventing affected virtual disks and dependent workloads from coming online.
- [File History (known issue)] Fixed: This update addresses an issue where File History might fail to back up or restore files to an external drive or network location. Affected devices might incorrectly display a “Reconnect your drive” message even when a compatible backup drive is connected and working properly.
- [Secure Boot] This update continues the deployment of updated Secure Boot certificates using the latest high-confidence targeting data to identify eligible devices that are ready to automatically receive the new certificates. Deployment through Windows Update remains ongoing across supported device.
Microsoft says the update has a known issue affecting some USB Audio Class 1.0 devices after installing the September 2026 Windows security updates.
Affected devices may fail to start with a Code 10 error in Device Manager, stop producing audio, or experience unresponsive volume controls and sound settings. Some devices may also work in standard stereo mode but fail when using 8-channel or 3D audio configurations.
Microsoft partially fixed the issue in an emergency out-of-band update released on September 14, which addressed problems with 8-channel and 3D audio modes.
However, other audio issues remain unresolved, and Microsoft says it is working on additional fixes.
Join Mikko Hyppönen and security leaders from the NFL, CHANEL, and Atlassian for a two-hour digital summit on what AI-speed attacks change, what defenders should stop doing, and how to validate, decide, fix, and re-validate at machine speed.