CVE-2026-45108
CVE-2026-45108 is a high-severity vulnerability with a CVSS 3.x base score of 8.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.
Key facts
- Severity: High (CVSS 3.x base score 8.4)
- EPSS exploit prediction: 0% (16th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-32633
- Weakness: CWE-863
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-45108?
- 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.
- How severe is CVE-2026-45108?
- CVE-2026-45108 has a CVSS 3.x base score of 8.4, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.
- Is CVE-2026-45108 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-45108?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-45108 have an EU (EUVD) identifier?
- Yes. CVE-2026-45108 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32633.
- When was CVE-2026-45108 published?
- CVE-2026-45108 was published on 2026-05-27 and last updated on 2026-06-17.
References
Other CWE-863 (Incorrect Authorization) vulnerabilities
- CVE-2026-48286 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) versions 7.4.3 build 9396 and earlier are affected by an Incorrect Authorization…
- CVE-2026-48303 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) versions 7.4.3 build 9394 and earlier are affected by an Incorrect Authorization…
- CVE-2026-44330 — Critical (CVSS 10.0): free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the…
- CVE-2026-46595 — Critical (CVSS 10.0): Previously, CVE-2024-45337 fixed an authorization bypass for misused ssh server configurations; if any other type of…
- CVE-2026-33105 — Critical (CVSS 10.0): Improper authorization in Microsoft Azure Kubernetes Service allows an unauthorized attacker to elevate privileges over…
- CVE-2026-32213 — Critical (CVSS 10.0): Improper authorization in Azure AI Foundry allows an unauthorized attacker to elevate privileges over a network.
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