CVE-2021-31950: Microsoft SharePoint Server Spoofing Vulnerability

Security readout for executives and security teams

CVE-2021-31950 is a high-severity Microsoft SharePoint Server spoofing vulnerability. It affects listed SharePoint 2013 Foundation SP1, SharePoint Enterprise Server 2016, and SharePoint Server 2019 versions. The business risk is unauthorized trust manipulation with high confidentiality impact, but provided scoring indicates attacker authentication and user interaction are required. Organizations running affected Microsoft SharePoint Foundation 2013 SP1, SharePoint Enterprise Server 2016, or SharePoint Server 2019 are potentially exposed, especially where SharePoint is reachable by many authenticated users or exposed through intranet, partner, or internet-facing portals. Treat this as a high-priority SharePoint patching item, especially for externally reachable collaboration portals. It is not marked as known exploited in the provided sources, but the confidentiality impact and public reference justify timely remediation. Mitigation focus: Review the Microsoft MSRC advisory for the official security update and deployment guidance.; Patch affected SharePoint 2013 SP1, 2016, and 2019 deployments according to Microsoft guidance.; Prioritize externally reachable or broadly accessible SharePoint farms..

Prepared

May 24, 2026, 01:29 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.