CVE-2026-45480: Azure AD Privilege Escalation Flaw

CVE-2026-45480 Overview

CVE-2026-45480 is an improper authentication vulnerability in Microsoft Azure Active Directory. An unauthenticated remote attacker can elevate privileges over the network without user interaction. The flaw is tracked under CWE-287 (Improper Authentication) and carries a maximum CVSS score of 10.0 with a scope change, meaning successful exploitation impacts resources beyond the vulnerable component.

Microsoft published the advisory through the Microsoft Security Response Center. The vulnerability affects Microsoft Azure Active Directory cloud identity infrastructure, exposing tenants to unauthorized privilege escalation against directory resources, federated applications, and downstream Microsoft 365 workloads.

Critical Impact
Unauthenticated network attackers can elevate privileges across Azure AD tenants, potentially compromising identity, access control, and federated workloads with no user interaction required.

Affected Products

Microsoft Azure Active Directory (cloud identity service)
Applications and workloads federated to affected Azure AD tenants
Microsoft 365 services relying on Azure AD authentication

Discovery Timeline

2026-06-19 - CVE-2026-45480 published to the National Vulnerability Database
2026-06-24 - Last updated in NVD database

Technical Details for CVE-2026-45480

Vulnerability Analysis

The vulnerability resides in the authentication flow of Microsoft Azure Active Directory. An attacker reaches the vulnerable component over the network with no prior credentials and no user interaction. Successful exploitation results in confidentiality, integrity, and availability impact on resources outside the authentication boundary because the CVSS scope is marked as Changed.

Azure AD issues tokens that authorize access to Microsoft 365, federated SaaS applications, and Azure resource management APIs. A flaw in the authentication path therefore extends beyond the identity provider itself. An attacker who bypasses authentication can request tokens or assume identities mapped to elevated directory roles.

The Exploit Prediction Scoring System rates this issue at 0.562%, placing it in the 42nd percentile. No public proof-of-concept code is available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog at the time of writing.

Root Cause

The root cause is improper authentication [CWE-287] within Azure Active Directory. Microsoft has not disclosed the specific protocol or token validation path affected. Improper authentication weaknesses typically arise from missing identity verification steps, accepting forged credentials, or failing to validate token signatures, audiences, or issuers.

Attack Vector

The attack vector is network-based with low attack complexity, no required privileges, and no user interaction. An attacker sends crafted authentication requests to Azure AD endpoints and obtains elevated access. Because Azure AD is internet-facing by design, every tenant is reachable by unauthenticated attackers.

No verified exploit code is publicly available. Refer to the Microsoft Security Update CVE-2026-45480 advisory for vendor-provided technical guidance.

Detection Methods for CVE-2026-45480

Indicators of Compromise

Unexpected role assignments or directory role activations in Azure AD audit logs
Sign-ins from unfamiliar IP addresses or autonomous system numbers against privileged accounts
Token issuance events without a matching interactive or non-interactive sign-in record
New service principals, application registrations, or consent grants created outside change windows

Detection Strategies

Correlate Azure AD AuditLogs, SignInLogs, and RiskyUsers streams to identify privilege changes that lack a preceding authenticated session
Hunt for OAuth token requests where the issuer, audience, or appid claims do not match expected federation patterns
Alert on additions to high-value directory roles such as Global Administrator, Privileged Role Administrator, and Application Administrator

Monitoring Recommendations

Stream Azure AD logs to a SIEM or data lake and retain them for at least 90 days for retrospective hunting
Enable Microsoft Entra ID Protection risk detections and route high-risk sign-ins to security operations
Monitor conditional access policy changes and break-glass account usage for tampering

How to Mitigate CVE-2026-45480

Immediate Actions Required

Review the Microsoft Security Update CVE-2026-45480 advisory and apply vendor-directed remediations for your tenant
Audit all Global Administrator, Privileged Role Administrator, and Application Administrator role assignments
Rotate credentials and secrets for service principals and application registrations with elevated permissions
Review recent consent grants and remove unused or unrecognized applications

Patch Information

Microsoft addresses Azure Active Directory vulnerabilities through service-side updates delivered automatically to the cloud identity platform. Tenant administrators do not install patches but must follow any tenant configuration steps published in the Microsoft Security Response Center advisory.

Workarounds

Enforce phishing-resistant multifactor authentication on all privileged accounts using FIDO2 or certificate-based authentication
Apply conditional access policies that require compliant devices and trusted network locations for privileged role activation
Use Privileged Identity Management to convert standing administrative access to just-in-time eligible assignments
Restrict legacy authentication protocols and disable user consent for unverified applications

bash

# Example: enforce MFA-required conditional access via Microsoft Graph PowerShell
Connect-MgGraph -Scopes "Policy.ReadWrite.ConditionalAccess"

$params = @{
  displayName = "Require MFA for Privileged Roles"
  state = "enabled"
  conditions = @{
    users = @{
      includeRoles = @(
        "62e90394-69f5-4237-9190-012177145e10"  # Global Administrator
      )
    }
    applications = @{ includeApplications = @("All") }
  }
  grantControls = @{
    operator = "AND"
    builtInControls = @("mfa", "compliantDevice")
  }
}

New-MgIdentityConditionalAccessPolicy -BodyParameter $params