This security update includes improvements and fixes that were a part of update KB4493443 (released April 25, 2019) and addresses the following issues:
- Provides protections against a new subclass of speculative execution side-channel vulnerabilities, known as Microarchitectural Data Sampling, for 64-Bit (x64) versions of Windows (CVE-2019-11091, CVE-2018-12126, CVE-2018-12127, CVE-2018-12130). Use the registry settings as described in the Windows Client and Windows Server articles. (These registry settings are enabled by default for Windows Client OS editions, but disabled by default for Windows Server OS editions).
- Addresses an issue that may cause “Error 1309” while installing or uninstalling certain types of .msi and .msp files on a virtual drive.
- Addresses an issue that prevents the Microsoft Visual Studio Simulator from starting.
- Adds "gov.uk" to the HTTP Strict Transport Security Top Level Domains (HSTS TLD) for Internet Explorer.
- Addresses an issue that may cause the text, layout, or cell size to become narrower or wider than expected in Microsoft Excel when using the MS UI Gothic or MS PGothic fonts.
- Security updates to Windows App Platform and Frameworks, Microsoft Graphics Component, Windows Storage and Filesystems, Windows Cryptography, Windows Datacenter Networking, Windows Wireless Networking, Windows Kernel, and the Microsoft JET Database Engine.
For more information about the resolved security vulnerabilities, please refer to the Security Update Guide.