Critical SharePoint Vulnerability CVE-2026-63520 Hits 2026

**SharePoint Vulnerability CVE-2026-63520** is a newly disclosed high-severity remote code execution flaw in SharePoint's Business Connectivity Services (CVSS 8.1) that can enable arbitrary code execution with SharePoint service-account privileges and, when chained with CVE-2026-55040, create an unauthenticated RCE attack path against internet-facing SharePoint deployments; Microsoft and Rapid7 advise immediate patching, auditing of BCS usage and internet exposure, monitoring for suspicious activity, and applying least-privilege controls, while no public exploitation has been reported at disclosure.