The WSO2 API Manager developer portal accepts user-supplied input without enforcing expected validation constraints or proper output encoding. This deficiency allows a malicious actor to inject script content that is executed within the context of a user's browser. By leveraging this cross-site scripting vulnerability, a malicious actor can cause the browser to redirect to a malicious website, make changes to the UI of the web page, or retrieve information from the browser.

However, session hijacking is not possible as all session-related sensitive cookies are protected by the httpOnly flag.