CVE-2026-55040

Name of the Vulnerable Software and Affected Versions Microsoft Office SharePoint (affected versions not specified)

Description Weak authentication in the JWT token validation pipeline allows an unauthenticated remote attacker to bypass security features over a network. Successful exploitation enables the attacker to perform operations as a SharePoint site user or administrator, potentially leading to remote code execution and privilege escalation on the server. Approximately 14,000 potentially exposed systems have been identified through internet-exposure search data, including infrastructure related to government, education, and commercial sectors across multiple countries.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.