SharePoint CVE-2026-55040 Comes Under Attack Following Public Exploit

Security Affairs reports active exploitation of a critical SharePoint authentication-bypass vulnerability following release of a public proof of concept, alongside ransomware, zero-day, supply-chain, botnet, autonomous intrusion, and data-extortion activity. The most urgent issue is CVE-2026-55040, reportedly enabling unauthenticated administrator impersonation with a CVSS score of 9.1. Other notable developments include StormEncryptor ransomware, Lazarus exploitation of a Windows zero-day, a Microsoft Defender patch bypass, a wormable DNS RCE, and a critical Zoom zero-click RCE.