KB4577021

Updates time zone information for the Yukon, Canada.

Updates to improve security when using Microsoft Office products.

Updates to improve security when using input devices such as a mouse, keyboard, or pen.

Updates to improve security in the Microsoft Store.

Updates to improve security when Windows performs basic operations.

Updates for storing and managing files.

Addresses a security vulnerability issue with user proxies and HTTP-based intranet servers. After installing this update, HTTP-based intranet servers cannot leverage a user proxy by default to detect updates. Scans using these servers will fail if the clients do not have a configured system proxy. If you must leverage a user proxy, you must configure the behavior using the Windows Update policy “Allow user proxy to be used as a fallback if detection using system proxy fails.” This change does not affect customers who secure their Windows Server Update Services (WSUS) servers with the Transport Layer Security (TLS) or Secure Sockets Layer (SSL) protocols. For more information, see Improving security for devices receiving updates via WSUS.

Updates time zone information for the Yukon, Canada.

Security updates to Windows App Platform and Frameworks, Microsoft Graphics Component, Windows Input and Composition, Windows Media, Windows Shell, the Microsoft Store, Windows Cloud Infrastructure, Windows Fundamentals, Windows Kernel, Windows Virtualization, Windows Storage and Filesystems, the Microsoft Scripting Engine, and the Microsoft JET Database Engine.