A reflected cross-site scripting (XSS) vulnerability exists in the sub-organization login flow of WSO2 Identity Server 7.0.0 due to improper input validation. A malicious actor can exploit this vulnerability to inject arbitrary JavaScript into the login flow, potentially leading to UI modifications, redirections to malicious websites, or data exfiltration from the browser. While this issue could allow an attacker to manipulate the user’s browser, session-related sensitive cookies remain protected with the httpOnly flag, preventing session hijacking.