It’s not generally available yet, but Microsoft has already issued the second quality update for Windows 10 version 1903. The update, which is, of course, cumulative, increments the build number to 18362.113.

“This update includes updates that come as part of the normal monthly release cycle,” a Microsoft support note explains.

Key changes include:

• Protections against a new subclass of speculative execution side-channel vulnerabilities, known as Microarchitectural Data Sampling, for 64-Bit (x64) versions of Windows (CVE-2018-11091,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 and Windows Server OS editions).
• Addresses an issue that decreases Internet Explorer’s performance when you use roaming profiles or you don’t use the Microsoft Compatibility List.
• 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.

This update is available normally via Windows Update, and you don’t have to be in the Windows Insider program to receive it. (Though those who are in the Insider program and are running Windows 10 version 1903 will receive it as well.)