Exploitation18 Aug 2026·3 sources
Attackers Exploit SharePoint Authentication Bypass CVE-2026-55040 Following Public PoC Release
Attackers are using Rapid7's public proof of concept for CVE-2026-55040, a CVSS 9.1 SharePoint Server authentication bypass in JWT token validation that Microsoft patched on 14 July 2026. Honeypot operators reported attempts in August, with some recorded as early as 19 July, and CISA added the flaw to KEV on 18 August.
SharePointCVE-2026-55040Authentication Bypass+2
