Himmelblau is an interoperability suite for Microsoft Azure Entra ID and Intune. From 2.0.0 to before 3.1.5 and 2.3.11, Himmelblau contained an authentication bypass vulnerability in the Device Authorization Grant (DAG) flow that allowed a user within the same Entra ID domain to obtain a local Unix session as another user by providing their own valid credentials. The vulnerability existed in the token_validate function, which validated domain aliases for legitimate multi-domain scenarios but failed to verify that the local part (username) of the authenticated user's UPN matched the requested account username. The function only compared domains, not the complete usernames. This vulnerability is fixed in 3.1.5 and 2.3.11.

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History

Thu, 28 May 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 28 May 2026 03:30:00 +0000

Type Values Removed Values Added
First Time appeared Himmelblau-idm
Himmelblau-idm himmelblau
Vendors & Products Himmelblau-idm
Himmelblau-idm himmelblau

Wed, 27 May 2026 19:30:00 +0000

Type Values Removed Values Added
Description Himmelblau is an interoperability suite for Microsoft Azure Entra ID and Intune. From 2.0.0 to before 3.1.5 and 2.3.11, Himmelblau contained an authentication bypass vulnerability in the Device Authorization Grant (DAG) flow that allowed a user within the same Entra ID domain to obtain a local Unix session as another user by providing their own valid credentials. The vulnerability existed in the token_validate function, which validated domain aliases for legitimate multi-domain scenarios but failed to verify that the local part (username) of the authenticated user's UPN matched the requested account username. The function only compared domains, not the complete usernames. This vulnerability is fixed in 3.1.5 and 2.3.11.
Title Himmelblau: Authentication Bypass via Cross-User Local Session Impersonation in Device Authorization Grant (DAG) Flow
Weaknesses CWE-863
References
Metrics cvssV3_1

{'score': 8.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-28T13:54:57.795Z

Reserved: 2026-05-08T19:27:26.699Z

Link: CVE-2026-45108

cve-icon Vulnrichment

Updated: 2026-05-28T13:54:52.675Z

cve-icon NVD

Status : Received

Published: 2026-05-27T20:16:38.550

Modified: 2026-05-27T20:16:38.550

Link: CVE-2026-45108

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-28T03:15:05Z

Weaknesses