CVE-2026-50366 in Windows
Summary
by MITRE • 07/14/2026
Null pointer dereference in Active Directory Domain Services allows an authorized attacker to deny service over a network.
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Analysis
by VulDB Data Team • 07/14/2026
A null pointer dereference vulnerability within Active Directory Domain Services represents a critical denial of service weakness that can be exploited by authenticated attackers to disrupt directory services availability. This flaw manifests when the domain services component attempts to access a null memory reference during processing of specific network requests, leading to unexpected service termination or system instability. The vulnerability specifically impacts the core directory service functionality that manages user authentication, authorization, and resource access across enterprise networks. According to CWE-476, this classification identifies the weakness as a pointer dereference on a null pointer, which directly translates to unauthorized service disruption when legitimate requests trigger the problematic code path.
The technical exploitation of this vulnerability requires an authenticated network connection to the affected domain services instance, making it accessible to users with valid credentials within the domain environment. Attackers can craft malicious requests that force the domain controller to process null references, causing the service to crash or become unresponsive. This behavior aligns with ATT&CK technique T1499.004 which covers network denial of service attacks targeting domain services. The operational impact extends beyond simple service interruption as domain controllers serve as critical infrastructure components that authenticate thousands of users and devices across enterprise networks, making this vulnerability particularly dangerous.
When exploited successfully, the null pointer dereference causes domain services to terminate unexpectedly or enter a non-responsive state, preventing legitimate authentication requests from being processed. This disruption affects not only user login capabilities but also impacts applications and systems that depend on Active Directory for credential validation and access control decisions. The attack vector typically involves sending specially crafted LDAP or RPC requests that trigger the vulnerable code path, with the null pointer dereference occurring during object processing or attribute handling within the directory service components.
Organizations should implement immediate mitigations including applying relevant security patches from Microsoft that address the specific null pointer dereference in Active Directory Domain Services. Network segmentation and access controls can limit potential attack surfaces by restricting unauthorized authentication attempts to domain controllers. Monitoring solutions should be configured to detect unusual patterns of authentication failures or service disruptions that might indicate exploitation attempts. Additionally, implementing redundant domain controller configurations provides fault tolerance and reduces single points of failure when vulnerabilities are exploited. The vulnerability demonstrates the critical importance of maintaining up-to-date security patches for core infrastructure components and highlights the need for comprehensive vulnerability management programs that prioritize authentication service weaknesses.