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.

Security researchers say Microsoft customers should take immediate action to defend against the ongoing cyberattacks, and must assume they have already been compromised.

Microsoft, in an alert posted Saturday, July 19, said the vulnerability enables an “authorized attacker to perform spoofing over a network,” a type of cyberattack in which an attacker attempts to trick a user or system into believing they are a trusted or known source.