CVE-2026-50652 in Azure Active Directory
Summary
by MITRE • 07/14/2026
Deserialization of untrusted data in Azure Active Directory allows an unauthorized attacker to deny service over a network.
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Analysis
by VulDB Data Team • 07/14/2026
This vulnerability represents a critical deserialization flaw within Azure Active Directory that enables remote attackers to execute denial of service attacks against the authentication infrastructure. The weakness stems from insufficient validation of user-supplied data during the deserialization process, allowing malicious actors to craft specially formatted payloads that can disrupt normal authentication operations. When Azure Active Directory processes untrusted input through its deserialization mechanisms, it fails to properly sanitize or validate the incoming data structure, creating an attack surface where crafted objects can trigger unexpected behavior within the system's processing pipeline.
The technical implementation of this vulnerability aligns with common CWE classifications related to insecure deserialization patterns, specifically CWE-502 which addresses deserialization of untrusted data. Attackers can exploit this weakness by sending malformed serialized objects that when processed by the Azure AD service cause resource exhaustion, application crashes, or abnormal termination of authentication services. The operational impact extends beyond simple service disruption as it can affect enterprise-wide authentication capabilities, potentially compromising business continuity and user access to critical applications and resources that depend on Active Directory for identity management.
From an attack framework perspective, this vulnerability maps to several ATT&CK techniques including T1498 for network denial of service and T1566 for initial access through malicious input. The attack vector typically involves sending crafted serialized data through API endpoints or authentication protocols that Azure AD uses to process user credentials and authentication requests. The system's failure to implement proper input validation, object type checking, or secure deserialization practices creates opportunities for attackers to manipulate the service's internal state. This weakness is particularly dangerous in enterprise environments where Azure AD serves as a central authentication hub for multiple applications and services.
Mitigation strategies should focus on implementing robust input validation controls at all entry points where user data is processed, including the implementation of strict object type restrictions during deserialization operations. Organizations must deploy proper serialization frameworks that enforce secure coding practices and avoid using default deserialization methods that accept arbitrary objects. Network-level protections such as rate limiting, API throttling, and intrusion detection systems can help detect and prevent exploitation attempts. Additionally, regular security assessments should validate that Azure AD configurations properly enforce data validation policies and that monitoring systems are in place to detect anomalous deserialization activity. The implementation of principle of least privilege access controls and regular security updates for Azure services further reduces the attack surface and potential impact of such vulnerabilities.