Microsoft has published the May 2021 security updates.

May 2021 Security Updates

Updates this Month

This release consists of security updates for the following products, features and roles.

• .NET Core & Visual Studio
• HTTP.sys
• Internet Explorer
• Microsoft Accessibility Insights for Web
• Microsoft Bluetooth Driver
• Microsoft Dynamics Finance & Operations
• Microsoft Exchange Server
• Microsoft Graphics Component
• Microsoft Office
• Microsoft Office Access
• Microsoft Office Excel
• Microsoft Office SharePoint
• Microsoft Office Word
• Microsoft Windows Codecs Library
• Microsoft Windows IrDA
• Open Source Software
• Role: Hyper-V
• Skype for Business and Microsoft Lync
• Visual Studio
• Visual Studio Code
• Windows Container Isolation FS Filter Driver
• Windows Container Manager Service
• Windows Cryptographic Services
• Windows CSC Service
• Windows Desktop Bridge
• Windows OLE
• Windows Projected File System FS Filter
• Windows RDP Client
• Windows SMB
• Windows SSDP Service
• Windows WalletService
• Windows Wireless Networking

Please note the following information regarding the security updates:

Security Update Guide Blog Posts

Date	Blog Post
February 9, 2021	Continuing to Listen: Good News about the Security Update Guide API
January 13, 2021	Security Update Guide Supports CVEs Assigned by Industry Partners
December 8, 2020	Security Update Guide: Let’s keep the conversation going
November 9, 2020	Vulnerability Descriptions in the New Version of the Security Update Guide

Relevant Information

• Windows 10 updates are cumulative. The monthly security release includes all security fixes for vulnerabilities that affect Windows 10, in addition to non-security updates. The updates are available via the Microsoft Update Catalog. For information on lifecycle and support dates for Windows 10 operating systems, please see Windows Lifecycle Facts Sheet.
• Microsoft is improving Windows Release Notes. For more information, please see What's next for Windows release notes.
• A list of the latest servicing stack updates for each operating system can be found in ADV990001. This list will be updated whenever a new servicing stack update is released. It is important to install the latest servicing stack update.
• In addition to security changes for the vulnerabilities, updates include defense-in-depth updates to help improve security-related features.
• Customers running Windows 7, Windows Server 2008 R2, or Windows Server 2008 need to purchase the Extended Security Update to continue receiving security updates. See 4522133 for more information.

FAQs, Mitigations, and Workarounds

The following CVEs have FAQs, Mitigations, or Workarounds. You can see these in more detail from the Vulnerabilities tab by selecting FAQs, Mitigations and Workarounds columns in the Edit Columns panel.

• CVE-2020-24587
• CVE-2021-1720
• CVE-2021-26419
• CVE-2021-28455
• CVE-2021-28465
• CVE-2021-28474
• CVE-2021-28479
• CVE-2021-31166
• CVE-2021-31171
• CVE-2021-31173
• CVE-2021-31174
• CVE-2021-31175
• CVE-2021-31176
• CVE-2021-31177
• CVE-2021-31178
• CVE-2021-31179
• CVE-2021-31180
• CVE-2021-31184
• CVE-2021-31186
• CVE-2021-31191
• CVE-2021-31205
• CVE-2021-31206
• CVE-2021-31207
• CVE-2021-31209
• CVE-2021-31211
• CVE-2021-31213
• CVE-2021-31214
• CVE-2021-31936

Known Issues

You can see these in more detail from the Deployments tab by selecting Known Issues column in the Edit Columns panel.

For more information about Windows Known Issues, please see Windows message center (links to currently-supported versions of Windows are in the left pane).

KB Article	Applies To
5003169	Windows 10, Version 1909, Windows Server, Version 1909
5003171	Windows 10, Version 1809, Windows Server 2019
5003173	Windows 10, Version 2004, Windows Server, Version 2004, Windows 10, Version 20H2, Windows Server, Version 20H2
5003197	Windows 10, Version 1607, Windows Server 2016
5003203	Windows Server 2012 (Security-only update)
5003208	Windows Server 2012 (Monthly Rollup)
5003209	Windows 8.1, Windows Server 2012 R2 (Monthly Rollup)
5003210	Windows Server 2008 SP2 (Monthly Rollup)
5003220	Windows 8.1 Windows Server 2012 R2 (Security-only update)
5003225	Windows Server 2008 SP2 (Security-only update)
5003228	Windows 7 SP2, Windows Server 2008 R2 (Security-only update)
5003233	Windows 7 SP2, Windows Server 2008 R2 (Monthly Rollup)
5003435	Exchange Server 2019, 2016, and 2013

Security Update Guide - Microsoft Security Response Center