A remote code execution vulnerability exists in Microsoft SharePoint Server when it fails to properly identify and filter unsafe ASP.Net web controls, aka 'Microsoft SharePoint Server Remote Code Execution Vulnerability'.
https://www.tenable.com/blog/microsoft-s-may-2020-patch-tuesday-addresses-111-cves
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1069