External risk intelligence

Azure Entra ID Authentication Bypass Vulnerability.

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2025-59246

Azure Entra ID is a cloud-based identity and access management service that is public-facing by design. As an identity provider, its endpoints are exposed to the internet to facilitate authentication and authorization for web applications, APIs, and enterprise services globally.

Missing Authentication

Microsoft Entra Id

Halo Surface Signal: 5 out of 5 — more likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in Azure Entra ID, Microsoft's cloud-based identity and access management service. This issue could allow unauthorized access and control over systems and data, potentially impacting user authentication and authorization processes across the services that rely on Azure Entra ID.

Unauthorized access to user identities and data.
Impacts cloud identity management and access controls.
Confirm relevance and exposure to Azure Entra ID.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by sending specially crafted requests to Azure Entra ID. This could allow them to gain elevated privileges within the system, potentially leading to unauthorized access to sensitive information or the ability to perform administrative actions.

Accessible via the network.
Specially crafted requests.
Unauthorized access and actions.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow an unauthenticated attacker to gain elevated privileges within Azure Entra ID, potentially impacting the integrity and availability of the service. Access to sensitive information is not explicitly mentioned as a risk in the provided context.

Azure Entra ID service integrity.
Unauthenticated network access.
Service disruption or unauthorized actions.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability impacts Azure Entra ID, a cloud-based identity service. Responsibility for addressing this critical issue likely falls to the platform or cloud infrastructure teams managing Entra ID, in coordination with the security team responsible for its configuration and the vendor management team overseeing the Microsoft relationship. The immediate first step is to confirm the scope and business criticality of Entra ID instances and identify the accountable owners for each.

Platform or Cloud Infrastructure teams.
Verify Entra ID reachability and criticality.
Plan coordinated remediation with Microsoft.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is Azure Entra ID?

Azure Entra ID is Microsoft’s cloud-based identity and access management service. Organizations use it to authenticate users and control access to internal resources, web applications, and APIs across their enterprise environment. It acts as the central hub for managing who has permission to access digital assets.

What does CVE-2025-59246 mean for security?

This vulnerability is classified as CWE-306, which refers to a Missing Authentication for Critical Function. In the context of this CVE, it means the system may perform sensitive actions without properly verifying the user's identity first, creating a significant security gap in the authentication process.

How can an attacker trigger this vulnerability?

An attacker triggers this bug by sending specially crafted network requests to the service. Because the vulnerability involves missing authentication, it does not require valid credentials or a user to interact with the service; it is the unexpected nature of the requests that bypasses normal security checks.

Is my organization at risk from this CVE?

Halo Surface Signal notes that Azure Entra ID is a cloud-based identity provider, meaning its endpoints are public-facing by design to support global authentication. Because it is inherently exposed to the internet, any organization using this service as its primary identity management platform must consider this vulnerability relevant to their environment.

How do I start addressing this vulnerability?

Since this is a cloud service vulnerability, the primary step is to identify the business criticality and configuration of your Entra ID instances. Coordinate with the teams managing your Microsoft vendor relationship to verify the status of the service and track guidance provided by Microsoft for any necessary configuration changes or updates.

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2025-59246

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.