CVE-2026-40379
CVE-2026-40379 is a critical-severity vulnerability in Microsoft Entra Id with a CVSS 3.x base score of 9.3. 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-200.
Key facts
- Severity: Critical (CVSS 3.x base score 9.3)
- EPSS exploit prediction: 1% (56th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-29655
- Weakness: CWE-200
- Affected product: Microsoft Entra Id
- Published:
- Last modified:
Description
Exposure of sensitive information to an unauthorized actor in Azure Entra ID allows an unauthorized attacker to perform spoofing over a network.
Frequently asked questions
- What is CVE-2026-40379?
- Exposure of sensitive information to an unauthorized actor in Azure Entra ID allows an unauthorized attacker to perform spoofing over a network.
- How severe is CVE-2026-40379?
- CVE-2026-40379 has a CVSS 3.x base score of 9.3, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
- Is CVE-2026-40379 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-40379?
- CVE-2026-40379 affects Microsoft Entra Id. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2026-40379?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- Does CVE-2026-40379 have an EU (EUVD) identifier?
- Yes. CVE-2026-40379 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29655.
- When was CVE-2026-40379 published?
- CVE-2026-40379 was published on 2026-05-12 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:microsoft:entra_id:-:*:*:*:*:*:*:*
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