Microsoft has released October 2021 security updates for Windows 10/8/7, Windows Server 2016/2012/2008, and Exchange Server 2019/2016/2013.
These updates include 39 security fixes, including fixes for critical security issues. Users should update as soon as possible to avoid potential exploitation.
System administrators should update servers as soon as possible to avoid potential exploitation.
How to update Windows
October 2021 Security Updates (Release Notes)