KB5126657

Microsoft has released cumulative update KB5126657 for Windows 10, version 22H2, as part of the October 2026 Patch Tuesday. It is intended for devices enrolled in the Extended Security Updates (ESU) program. Build 19045.7807 is a quality update and includes no new system features. In the October Patch Tuesday, Microsoft fixed 1411 security issues, including three zero-day vulnerabilities.

• Security. The update contains various security improvements for internal OS functionality for October 2026.
• Secure Boot. The rollout of updated Secure Boot certificates continues. Up-to-date, high-confidence data is used to identify devices that are ready to receive the new certificates automatically. The rollout through Windows Update continues on supported devices.
• File History. Fixed an issue where File History might fail to back up or restore files on an external drive or in a network location. On affected devices, the message Reconnect your drive could appear by mistake, even when a compatible backup drive was connected and working properly.
• Date and time. Added support for permanent daylight saving time in British Columbia and Alberta starting in November 2026, as well as a new Manitoba time zone (UTC-05:00).
• Storage Spaces. Fixed an issue with Storage Spaces Direct virtual disks that use storage tiers. After installing certain security updates, some virtual disks might fail to come online, making dependent clustered workloads unavailable.
• ReFS security. Auditing and additional policy-based controls have been added for ReFS volumes on external drives. Auditing is enabled by default, while enforcement is disabled, so administrators can evaluate and prepare for upcoming security hardening changes.

Known issues:

• Audio on USB Audio Class 1.0 devices. After installing KB5124012, some USB Audio Class 1.0 devices might stop playing sound. The error This device cannot start (Code 10), volume control failures, and unavailable sound settings may occur. Update KB5129195 fixes failures in eight-channel and 3D audio modes, but the other symptoms persist for now. In some cases, switching to two-channel mode helps. Microsoft is working on a full fix.

Cumulative update KB5126657 is installed automatically on PCs through Windows Update. To check, go to Settings > Update & Security and click Check for updates. If you have installed previous updates, only the new updates contained in this package will be downloaded and installed on your device.

Along with the cumulative update, Microsoft released a dynamic update for Windows 10 versions 22H2 and 21H2 on October 13. Safe OS Dynamic Update KB5126665 updates the WinRE recovery environment to version 10.0.19041.7801. There is no new Setup Dynamic Update package this month. The package is installed automatically through Windows Update, and manual installation is mainly needed when preparing installation images.

The last 10 Windows updates: