IMPORTANT We have been evaluating the public health situation, and we understand this is impacting our customers. In response to these challenges, we are prioritizing our focus on security updates. Starting in May 2020, we are pausing all optional non-security releases (C and D updates) for all the supported versions of Windows client and server products (Windows 10, version 1909 down to Windows Server 2008 SP2).
There is no change to the monthly security updates (B release – Update Tuesday); these will continue as planned to ensure business continuity and to keep our customers protected and productive.
Improvements and fixes
This security update includes improvements and fixes that were a part of update KB4550958 (released April 21, 2020) and addresses the following issues:
- Updates the 2020 start date for daylight saving time (DST) in the Kingdom of Morocco. For more information, see KB4557900.
- Addresses an issue that causes offline file syncing to stop responding or fail in mobsyc.exe.
- Security updates to Internet Explorer, the Microsoft Scripting Engine, Windows App Platform and Frameworks, Windows Input and Composition, Windows Media, Windows Kernel, Windows Core Networking, Internet Information Services, Windows Network Security and Containers, Windows Active Directory, the Microsoft JET Database Engine, and Windows Storage and Filesystems.
For more information about the resolved security vulnerabilities, please refer to the Security Update Guide.
Known issues in this update
|Certain operations, such as rename, that you perform on files or folders that are on a Cluster Shared Volume (CSV) may fail with the error, “STATUS_BAD_IMPERSONATION_LEVEL (0xC00000A5)”. This occurs when you perform the operation on a CSV owner node from a process that doesn’t have administrator privilege.|| |
Do one of the following:
Microsoft is working on a resolution and will provide an update in an upcoming release.
How to get this update
Before installing this update
Microsoft strongly recommends you install the latest servicing stack update (SSU) for your operating system before installing the latest Rollup. SSUs improve the reliability of the update process to mitigate potential issues while installing the Rollup and applying Microsoft security fixes. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.
Install this update
|Release Channel||Available||Next Step|
|Windows Update and Microsoft Update||Yes||None. This update will be downloaded and installed automatically from Windows Update.|
|Microsoft Update Catalog||Yes||To get the standalone package for this update, go to the Microsoft Update Catalog website.|
|Windows Server Update Services (WSUS)||Yes|| |
This update will automatically sync with WSUS if you configure Products and Classifications as follows:
Product: Windows 8.1, Windows Server 2012 R2, Windows Embedded 8.1 Industry Enterprise, Windows Embedded 8.1 Industry ProClassification: Security Updates
For a list of the files that are provided in this update, download the file information for update 4556846.