Releasing Windows 10 Build 19043.928 (21H1) to Beta & Release Preview Channels

Hello Windows Insiders, today we’re releasing 21H1 Build 19043.928 (KB5001330) the Beta Channel for those Insiders who are on 21H1 (Click here for the 21H1 announcement). This update is also available for commercial devices in the Release Preview Channel on 21H1 as mentioned here in this blog post.

This security update includes quality improvements. Key changes include:

• We fixed an issue in which a principal in a trusted MIT realm fails to obtain a Kerberos service ticket from Active Directory domain controllers (DC). This occurs on devices that installed Windows Updates that contain CVE-2020-17049 protections and configured PerfromTicketSignature to 1 or higher. These updates were released between November 10, 2020 and December 8, 2020. Ticket acquisition also fails with the error, “KRB_GENERIC_ERROR”, if callers submit a PAC-less Ticket Granting Ticket (TGT) as an evidence ticket without providing the USER_NO_AUTH_DATA_REQUIRED flag.

• We fixed an issue with security vulnerabilities identified by a security researcher. Because of these security vulnerabilities, this and all future Windows updates will no longer contain the RemoteFX vGPU.For more information about the vulnerability and its removal, see CVE-2020-1036 and KB4570006. Secure vGPU alternatives are available using Discrete Device Assignment (DDA) in Windows Server LTSC releases (Windows Server 2016 and Windows Server 2019) and Windows Server SAC releases (Windows Server, version 1803 and later versions).
• We fixed a potential elevation of privilege vulnerability in the way Azure Active Directory web sign-in allows arbitrary browsing from the third-party endpoints used for federated authentication. For more information, see CVE-2021-27092 and Policy CSP – Authentication.

• Security updates to Windows App Platform and Frameworks, Windows Apps, Windows Input and Composition, Windows Office Media, Windows Fundamentals, Windows Cryptography, the Windows AI Platform, Windows Kernel, Windows Virtualization, Internet Explorer, and Windows Media.

• We have resolved an issue where some Insiders were getting an 0x800f081f error when attempting to install an early version of KB5000842. If you continue to hit an issue with the final version of KB5000842 update, let us know via Feedback Hub.

For more information about the resolved security vulnerabilities, please refer to the new Security Update Guide website.

Please note it may take up to an hour after going live for the KB article to show up on the Windows 10 update history page.

Thanks,
The Windows Insider Program Team