CVE-2026-45108

high

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.

References

https://github.com/himmelblau-idm/himmelblau/security/advisories/GHSA-pmxh-j4r6-88mv

Details

Source: Mitre, NVD

Published: 2026-05-27

Updated: 2026-05-27

Risk Information

CVSS v2

Base Score: 6.8

Vector: CVSS2#AV:N/AC:H/Au:S/C:C/I:C/A:P

Severity: Medium

CVSS v3

Base Score: 8.4

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

Severity: High