A reflected cross-site scripting (XSS) vulnerability exists in the authentication endpoints of multiple WSO2 products due to a lack of output encoding. A malicious actor can inject arbitrary JavaScript payloads into the authentication endpoint, which are reflected back in the response, enabling browser-based attacks. Exploitation may result in redirection to malicious websites, UI manipulation, or unauthorized data access from the victim’s browser.

However, session-related cookies are protected with the httpOnly flag, which mitigates session hijacking via this vector.