SharePoint CVE-2026-55040 Actively Exploited: AI-Discovered RCE Chain
CVE-2026-55040, a critical SharePoint authentication bypass, is now being actively exploited. A proof-of-concept went public on August 11. Within 24 hours, threat intelligence firm Defused confirmed exploitation attempts against its SharePoint honeypots using that same PoC. Over 8,500 SharePoint servers remain reachable from the open internet, putting unpatched instances at immediate risk.