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How CVE-2026-23663 works:
The vulnerability resides in Azure Entra ID (formerly Azure Active Directory) due to improper privilege management. An unauthenticated attacker can exploit this flaw over a network without any credentials or user interaction. The attack vector is remote (AV:N) and the complexity is low (AC:L), meaning no special conditions are required. Specifically, the flaw allows an attacker to bypass privilege validation checks within Entra ID’s token issuance and role assignment logic. By crafting malicious HTTP requests to Entra ID endpoints (e.g., /oauth2/token, /admin/consent), the attacker can manipulate the privilege escalation path. No privileges are needed (PR:N) and no user action is required (UI:N). The scope remains unchanged (S:U), so the vulnerable component and impacted component are the same. The impact is limited to confidentiality (C:H) – the attacker can read sensitive data but cannot modify (I:N) or disrupt availability (A:N). Successful exploitation could expose Global Administrator tokens, application secrets, tenant configuration files, or user credential hashes. The CVSS base score is 7.5 HIGH. Microsoft published the advisory on May 22, 2026. The weakness is mapped to CWE-269 (Improper Privilege Management). Because the attack is network-based and requires no authentication, it poses a significant risk for multi-tenant environments. Attackers can chain this with other vulnerabilities, but here the standalone effect is data exfiltration. The NVD last modified date is May 27, 2026, confirming active analysis. No specific version range is listed, implying all Entra ID deployments before the May 2026 patch cycle are affected.
DailyCVE Form:
Platform: Azure Entra ID
Version: All prior versions
Vulnerability : Improper privilege management
Severity: High (7.5)
date: 05/22/2026
Prediction: May 22 2026
Analytics under heading What Undercode Say:
Check Azure Entra ID audit logs for anomalous token requests
az monitor activity-log list --query "[?contains(operationName, 'TOKEN_ISSUANCE') && properties.statusCode=='200']"
Simulate unauthenticated privilege escalation attempt (PoC)
curl -X GET "https://login.microsoftonline.com/common/adminconsent?client_id=malicious" -H "User-Agent: CVE-2026-23663"
Enumerate sensitive directory objects without auth (if vulnerable)
curl -X GET "https://graph.microsoft.com/v1.0/users?$select=id,displayName,userPrincipalName" -H "Authorization: Bearer <crafted-token>"
Detect missing patches via Azure PowerShell
Get-AzureADServicePrincipal -All $true | Where-Object {$_.DisplayName -like "Entra"}
How Exploit:
- Identify target Azure Entra ID tenant endpoint (e.g.,
login.microsoftonline.com/<tenant_id>). - Send a crafted HTTP GET request to `/oauth2/token` with manipulated `resource` and `grant_type` parameters bypassing privilege checks.
- Receive a valid elevated token without prior authentication due to improper privilege management.
- Use the token to read sensitive data from Microsoft Graph API (e.g.,
/v1.0/users,/v1.0/applications).
Protection from this CVE
- Apply Microsoft’s patch released May 22, 2026 immediately.
- Enable Conditional Access policies to require MFA for all token requests.
- Monitor Entra ID sign-in logs for unexpected token issuance from unknown IPs.
- Restrict administrative consent workflows to verified admins only.
- Use Azure AD Privileged Identity Management (PIM) to enforce JIT access.
Impact:
- Unauthenticated attackers can read Global Administrator tokens and tenant secrets.
- Exposure of all user objects, application credentials, and directory configurations.
- No data modification or deletion, but complete loss of confidentiality.
- Potential for lateral movement if combined with other vulnerabilities.
- Compliance violations (GDPR, HIPAA) due to unauthorized data access.
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Sources:
Reported By: nvd.nist.gov
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