CVE-2026-50684 in Windows
Summary
by MITRE • 07/14/2026
Improper neutralization of input during web page generation ('cross-site scripting') in Active Directory Federation Services (AD FS) allows an authorized attacker to perform spoofing over a network.
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Analysis
by VulDB Data Team • 07/15/2026
Cross-site scripting vulnerabilities in active directory federation services represent a critical security weakness that enables authenticated attackers to manipulate web page content and conduct spoofing operations. This vulnerability stems from inadequate input validation and sanitization during the dynamic generation of web pages within the ad fs environment, creating opportunities for malicious actors to inject malicious scripts into user sessions. The flaw specifically manifests when the system fails to properly neutralize user-supplied data before incorporating it into web responses, allowing attackers with valid credentials to execute arbitrary javascript code in the context of other users' browsers.
The technical implementation of this vulnerability involves the manipulation of input parameters that are subsequently rendered in web interfaces without proper encoding or sanitization. When authenticated users interact with ad fs components, any unfiltered input can be processed and displayed in ways that permit script execution, particularly affecting the authentication and federation workflows where user interactions occur. The attack vector typically leverages the fact that legitimate users already possess valid session tokens and access rights within the system, making it easier to establish persistent malicious presence.
From an operational impact perspective, this vulnerability enables attackers to perform various spoofing operations including session hijacking, credential theft, and unauthorized access to protected resources. The attacker can manipulate web content to appear as legitimate system interfaces, tricking users into revealing sensitive information or performing unintended actions. This weakness particularly affects the federation trust relationships and authentication processes that ad fs manages, potentially allowing attackers to escalate privileges or gain access to additional systems within the federated environment.
The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws in web applications, and corresponds to techniques documented in the attack tactics framework under the execution and persistence categories. Ad fs administrators should implement comprehensive input validation mechanisms that properly encode all user-supplied data before rendering it in web contexts, including implementing proper content security policies and ensuring that all dynamic content generation processes sanitize inputs appropriately. Additional mitigations include regular security updates from microsoft, network segmentation to limit access to ad fs components, and monitoring for suspicious authentication patterns or unusual web request behaviors that may indicate exploitation attempts.