Microsoft SharePoint Server Vulnerability Enables Remote Code Execution Attacks

**CVE-2026-45659 — Microsoft SharePoint Server deserialization RCE:** Microsoft disclosed an important remote code execution vulnerability in on-premises SharePoint Server that allows authenticated users with Site Member permissions to trigger deserialization of untrusted data and execute arbitrary code remotely; patches were released on May 21, 2026, and organizations are urged to apply updates, audit permissions, monitor logs, and consider isolating internet-facing instances while no active exploitation has been reported.