CVE-2026-31957
criticalCVSS v3 Base Score
10.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS Score
0.2%
Exploitation probability in 30 days
Top 56% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Vulnerability Report
Generated by CyberWatcher
Description
Himmelblau is an interoperability suite for Microsoft Azure Entra ID and Intune. From 3.0.0 to before 3.1.0, if Himmelblau is deployed without a configured tenant domain in himmelblau.conf, authentication is not tenant-scoped. In this mode, Himmelblau can accept authentication attempts for arbitrary Entra ID domains by dynamically registering providers at runtime. This behavior is intended for initial/local bootstrap scenarios, but it can create risk in remote authentication environments. This vulnerability is fixed in 3.1.0.