May 12, 2020—KB4556812 (OS Build 16299.1868)

IMPORTANTWe have been evaluating the public health situation, and we understand the impact this is having on you, our valued customers. To ease one of the many burdens you are currently facing, we have decided to delay the scheduled end of service date for the Enterprise, Education, and IoT Enterprise editions of Windows 10, version 1709. This means devices will receive monthly security updates only from May to October. The final security update for these editions of Windows 10, version 1709 will be released on October 13, 2020 instead of April 14, 2020. For more information, please see the blog post on Tech Community.

ReminderMarch 12, 2019 and April 9, 2019 were the last two Delta updates for Windows 10, version 1709. Security and quality updates will continue to be available using the express and full cumulative update packages. For more information on this change please visit our blog.

Reminder Windows 10, version 1709, reached end of service on April 9, 2019 for devices running Windows 10 Home, Pro, Pro for Workstation, and IoT Core editions. These devices will no longer receive monthly security and quality updates that contain protection from the latest security threats. To continue receiving security and quality updates, Microsoft recommends updating to the latest version of Windows 10.

IMPORTANTWindows 10 Enterprise, Education, and IoT Enterprise editions will continue to receive servicing at no cost per the lifecycle announcement on October 2018.

ePub support ended in Microsoft EdgeMicrosoft Edge has ended support for e-books that use the .epub file extension. For more information, see Download an ePub app to keep reading e-books.

For more information about the various types of Windows updates, such as critical, security, driver, service packs, and so on, please see the following article.

Highlights

• Updates to improve security when using Internet Explorer and Microsoft Edge.
• Updates to improve security when using input devices such as a mouse, keyboard, or stylus.
• Updates to improve security when using Microsoft Xbox.
• Updates to improve security when Windows performs basic operations.
• Updates for storing and managing files.
• Updates to improve security when using external devices (such as game controllers, printers, and web cameras).

Improvements and fixes

This security update includes quality improvements. Key changes include:

• Addresses an issue that prevents certain apps from installing if they are published using a Group Policy Object.
• Updates the 2020 start date for daylight saving time (DST) in the Kingdom of Morocco.
• Addresses an issue that causes a memory leak in the LsaIso.exe process when the server is under a heavy authentication load and Credential Guard is enabled.
• Addresses an issue with running klist.exe that causeslsass.exe to stop working and generates an access violation error (0xC0000005).
• Addresses an issue that prevents Microsoft Internet Information Services (IIS) management tools, such as IIS Manager, from managing an ASP.NET application that has configured SameSite cookie settings inweb.config.
• Addresses an issue that prevents a call to NCryptGetProperty() from returning the correctpbOutputvalue whenpszProperty is set to “Algorithm Group” and you are using a Trusted Platform Module (TPM) 1.2 device.
• Security updates to Internet Explorer, the Microsoft Scripting Engine, Windows App Platform and Frameworks, Windows Input and Composition, Windows Media, Windows Shell, Microsoft Xbox, Microsoft Edge, Windows Fundamentals, Windows Cryptography, Windows Kernel, Windows Update Stack, Windows Core Networking, Windows Peripherals, Internet Information Services, Windows Network Security and Containers, Windows Active Directory, Windows Storage and Filesystems, and the Microsoft JET Database Engine.
  If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device.For more information about the resolved security vulnerabilities, please refer to the Security Update Guide.

Known issues in this update

Microsoft is not currently aware of any issues with this update.

How to get this update