CVE-2026-45659 — Microsoft SharePoint RCE (Exploited in Ransomware)

CVE-2026-45659 is a remote code execution vulnerability in Microsoft SharePoint Server, flagged as actively exploited since early July 2026 and, as of August, also being used in ransomware attacks — one of eight SharePoint flaws exploited by ransomware among the fifteen CISA has catalogued.

Type: Remote code execution | Exploitation: Active, used in ransomware | Mitigation: patch; audit SharePoint logs