Microsoft Windows 11 26H1 Update Version OS Build 28000.1719

KB5079466 updates Windows 11, version 26H1 to OS Build 28000.1719 with security improvements and non-security fixes from the February preview release. It also improves Secure Boot certificate targeting, WDAC COM object allowlisting, and Windows System Image Manager catalog trust handling. Reference IDs: KB5077239, KB5078262.

• Secure Boot: expands high-confidence device targeting data for automatic delivery of new Secure Boot certificates in a controlled, phased rollout.
• Windows Defender Application Control (WDAC): fixes COM objects being blocked when the endpoint security policy was set higher than the allowlisting policy.

• Windows System Image Manager: improves reliability when choosing trusted catalog files and adds a warning dialog to confirm the file comes from a trusted source.

• Includes fixes and quality improvements from KB5077239.
• If previous updates are already installed, only the new updates in this package will be downloaded and installed.
• Windows 11 servicing stack update (KB5078262) is included for OS Build 28000.1638.
• AI components updated: Image Search, Content Extraction, Semantic Analysis, and Settings Model to version 1.2601.1268.0.

Product Information

Vendor: Microsoft

Product: Windows 11

Product type: Software

Application category: Utilities

Platform: Windows

Variant: 26H1

Version: OS Build 28000.1719

Vendor information published: Mar 10, 2026

Original release notes: View on vendor site

Published on updatealert.io: Jun 3, 2026

Description: Client operating system for modern desktop and enterprise environments.