If exploited, attackers can gain full access to SharePoint content and potentially pivot to Outlook, Teams, and OneDrive. Learn how to protect your SharePoint server from compromise.

An ongoing cyberattack campaign known as “ToolShell” is exploiting on-premises Microsoft SharePoint Servers and has reportedly compromised organizations worldwide.

The term "zero-day" attack refers to when a previously unknown vulnerability is targeted. Tens of thousands of servers are said to be at risk. While the issue is serious, it differs from several previous vulnerabilities related to Microsoft. The attack only affects on-premises servers; cloud-based servers are unaffected.