Microsoft has released April 2021 security updates for Windows 10/8/7, Windows Server 2012/2008, Microsoft Exchange Server 2019/2016/2013, and SharePoint Server 2019.
These updates include 40 security fixes. Users should update as soon as possible to avoid potential exploitation.
System administrators should update servers immediately to mitigate newly disclosed Microsoft Exchange vulnerabilities.
How to update Windows
April 2021 Security Updates (Release Notes)