Improvements and fixes
This security update addresses the following issues:
Provides protections against an additional subclass of speculative execution side-channel vulnerability known as Speculative Store Bypass (CVE-2018-3639) for AMD-based computers. These protections aren't enabled by default. For Windows client (IT pro) guidance, follow the instructions in KB4073119. For Windows Server guidance, follow the instructions in KB4072698. Use these guidance documents to enable mitigations for Speculative Store Bypass (CVE-2018-3639). Additionally, use the mitigations that have already been released for Spectre Variant 2 (CVE-2017-5715) and Meltdown (CVE-2017-5754).
Addresses an issue that affects PowerShell remoting loop back using non-administrator accounts. For more details, see Windows Security change affecting PowerShell.
- Security updates to Windows App Platform and Frameworks, Windows MSXML, Windows Kernel, Windows Storage and Filesystems, Windows Wireless Networking, and the Microsoft JET Database Engine.
For more information about the resolved security vulnerabilities, please refer to the Security Update Guide.
Known issues in this update
|After installing this update, third-party applications may have difficulty authenticating hotspots.||This issue is resolved in KB4480969.|
|Applications that use a Microsoft Jet database with the Microsoft Access 97 file format may fail to open if the database has column names greater than 32 characters. The database will fail to open with the error, “Unrecognized Database Format”.|| |
This issue is resolved in KB4487000.
After installing this update, virtual machines (VM) may fail to restore successfully if the VM has been saved and restored once before. The error message is, “Failed to restore the virtual machine state: Cannot restore this virtual machine because the saved state data cannot be read. Delete the saved state data and then try to start the virtual machine. (0xC0370027).”
This affects AMD Bulldozer Family 15h, AMD Jaguar Family 16h, and AMD Puma Family 16h (second generation) microarchitectures.
This issue is resolved in KB4490512.
After installing this update, Internet Explorer 11 and other applications that use WININET.DLL may have authentication issues. This occurs when two or more people use the same user account for multiple, concurrent login sessions on the same Windows Server machine, including Remote Desktop Protocol (RDP) and Terminal Server logons. Symptoms reported by customers include, but may not be limited to:
This issue is resolved in KB4493446.
After installing this update, MSXML6 causes applications to stop responding if an exception was thrown during node operations, such as appendChild(), insertBefore(), and moveNode().The Group Policy editor may stop responding when editing a Group Policy Object (GPO) that contains Group Policy Preferences (GPP) for Internet Explorer 10 settings.
|This issue is resolved in KB4493446.|
|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.|| |
This issue is resolved in KB4550958 for all the releases from January 8, 2019 to April 14, 2020.