The U.S. EPA is issuing this alert to inform water and wastewater system owners and operators of the need for increased vigilance surrounding the use of Microsoft SharePoint. While the scope and impact continue to be assessed, the chain, publicly reported as “ToolShell,” provides unauthenticated access to systems and authenticated access through network spoofing, respectively, and enables malicious actors to fully access SharePoint content, including file systems and internal configurations, and execute code over the network. See a full update regarding this release on the CISA’s Webpage.