CVE-2026-31957 CRITICAL

CVE-2026-31957: Himmelblau unset domain configuration can allow any-tenant authentication at first login for remote deployments

Vendor Himmelblau-Idm
Product himmelblau
Weakness CWE-1188
Published March 11, 2026
Last update March 12, 2026
View on NVD All CVEs

CVSS base score

10.0/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

March 11, 2026 CVE published
March 12, 2026 Record updated