CVE-2026-20963

Microsoft SharePoint allows remote code execution via deserialization of untrusted data, confirmed as actively exploited.

This vulnerability enables an attacker to execute arbitrary code on Microsoft SharePoint servers by deserializing untrusted data, posing a severe risk to DIB organizations relying on SharePoint for sensitive data. Because it is actively exploited and linked to ransomware campaigns, organizations must immediately patch and review SharePoint configurations to prevent unauthorized access and data exfiltration.

Shame score — Active exploitation of a critical RCE vulnerability in a widely used product indicates a severe security posture failure.