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Azure Entra ID could allow external attackers to spoof identities and access sensitive data.

Azure Entra ID could allow external attackers to spoof identities, potentially exposing sensitive data and compromising administrative access. There is currently no evidence of active exploitation.

NVD published May 12, 2026 (3 days ago)

External risk briefCRITICAL

CVE-2026-40379

Halo Surface Signal

5/ 5

Azure Entra ID is a cloud-based identity and access management service. It is designed to be internet-accessible as an identity portal to manage authentication and access across organizations, placing it directly on the public-facing edge of the environment by design.

Exposure facts

H – Horizon Alert

A security vulnerability has been identified within Azure Entra ID that potentially allows unauthorized individuals to access sensitive information. This exposure could enable an attacker to perform network spoofing, which risks the integrity and trustworthiness of our communications. Addressing this issue is important to maintain the secure operation and reliability of our identity management environment.

A – Asset Exposure

This vulnerability impacts Azure Entra ID, the cloud-based service used to manage identities and access permissions across your organization. Because this service is accessible over the internet, an unauthorized actor could perform spoofing, which may compromise the integrity of your identity verification processes. Consequently, this could lead to the unauthorized access or misuse of sensitive information and admin access within your digital environment.

L – Live Threat

The available context for this vulnerability does not indicate active exploitation or observed targeting by malicious actors at this time. Because no live-threat signals are present, there is no evidence of elevated risk to the organization. Current information suggests a low likelihood of impact.

O – Operational Fix

Please coordinate with your IT and security teams to review the official guidance provided by the Microsoft Security Response Center. Because this issue involves potential information exposure within Azure Entra ID, the most effective next step is to apply any recommended vendor updates or configuration changes detailed in their documentation. We advise prioritizing a review of your current Azure identity configurations to ensure they align with the vendor’s latest security requirements.

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