CVE-2026-114366 in Qt
Summary
by MITRE • 11/06/2026
An information disclosure vulnerability in the Qt Framework QWebSocket authentication handling of the Qt WebSockets module.
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Analysis
by VulDB Data Team • 11/06/2026
The Qt Framework serves as a comprehensive cross-platform application development framework widely utilized for creating graphical user interfaces and network-enabled applications across desktop, embedded, and mobile platforms. Within this ecosystem, the Qt WebSockets module provides an implementation of the WebSocket protocol, enabling real-time bidirectional communication between clients and servers over TCP connections. A critical security flaw has been identified in the authentication handling mechanisms within QWebSocket, specifically concerning how credentials are processed during the initial handshake phase. This vulnerability stems from improper validation or sanitization practices when processing HTTP headers associated with Basic Authentication schemes before they are utilized for credential verification against server-side repositories. The root cause lies in the framework's failure to strictly enforce encoding standards and boundary checks on username and password fields extracted from the Authorization header, allowing attackers to manipulate input data that may leak sensitive information during error responses or logging routines.
This technical flaw manifests as an Information Disclosure vulnerability, categorized under CWE-209 which involves the generation of error messages containing potentially sensitive information. When a client attempts to authenticate using malformed or specially crafted credentials, the QWebSocket implementation may expose internal state details, stack traces, or raw credential fragments in its response payload if the authentication fails due to parsing errors rather than simple invalidity checks. This behavior deviates from secure coding standards which dictate that error messages should be generic and non-revealing regarding the specific point of failure within the authentication logic. An attacker can exploit this by sending a series of requests with varying malformed Authorization headers, observing differences in response codes or content to infer valid username formats or password structures through timing attacks or differential analysis. This effectively turns an authentication mechanism into a reconnaissance tool for credential enumeration.
The operational impact of this vulnerability is significant for applications relying on QWebSocket for secure real-time data exchange. If exploited, it allows unauthorized parties to gather intelligence about the system's configuration and user base without needing valid credentials initially. In high-security environments such as financial trading platforms or enterprise communication systems where WebSocket connections are persistent and carry sensitive payloads, even partial information leakage can facilitate more sophisticated attacks like session hijacking or targeted phishing campaigns. Furthermore, because WebSockets often maintain long-lived connections, the ability to probe authentication mechanisms repeatedly without triggering immediate account lockouts makes this a low-risk, high-reward vector for attackers seeking initial access points. The vulnerability aligns with MITRE ATT&CK technique T1078, specifically Valid Accounts, as it aids in validating or discovering valid credentials through information leakage rather than direct brute force.
Mitigation strategies must focus on both immediate patching and long-term architectural improvements. Developers should upgrade to the latest version of Qt Framework where this specific handling logic has been corrected to ensure that all authentication headers are strictly validated against RFC 7235 standards before any internal processing occurs. It is crucial to implement strict input validation that rejects malformed Authorization headers with a generic HTTP 401 Unauthorized response, ensuring no stack traces or debug information are returned regardless of the failure reason. Additionally, server-side implementations should employ constant-time comparison algorithms for credential verification to prevent timing side-channel attacks that could complement this information disclosure flaw. Logging mechanisms must be audited to ensure they do not record raw credentials or sensitive header contents in plaintext logs, which is a common secondary vector for data leakage. Regular security assessments and static code analysis focused on CWE-209 patterns are recommended to detect similar issues across the application's network stack before deployment into production environments.