Attackers Exploit SharePoint Authentication Bypass After Public PoC Release

Threat actors have begun to exploit a newly disclosed Microsoft SharePoint vulnerability following the release of a proof-of-concept PoC code. The vulnerability in question is CVE-2026-55040 CVSS score: 9.1, which refers to a critical security feature bypass that stems from weak authentication. I...

Researchers Disclose AI-Assisted SharePoint Exploit Chain Reaching Unauthenticated RCE

Security researchers found a way to enter Microsoft SharePoint servers as any user, including an administrator, with no valid account. A significant part of the work that found it was done through an AI agent. The flaw, tracked as CVE-2026-55040 CVSS 9.1, affects SharePoint Server Subscription...

Rapid7 Analysis: Microsoft SharePoint JWT Token Authentication Bypass (CVE-2026-55040)

Overview On July 14, 2026, Rapid7 and Microsoft disclosed CVE-2026-55040, an authentication bypass vulnerability affecting Microsoft SharePoint. Today we are publishing a technical analysis of the vulnerability along with an accompanying proof-of-concept PoC script. Figure 1: The Rapid7 Labs PoC...