HAX CMS helps manage microsite universe with PHP or NodeJs backends. Prior to version 26.0.0, an attack chain utilizing Stored XSS alongside dynamic token exposure in the /system/api/connectionSettings endpoint allows an authenticated attacker to perform a complete cross-tenant account takeover. The API dynamically leaks the active session's authentication tokens (including the jwt, user_token, site_token, and appstore_token) into a global JavaScript variable (window.appSettings). An attacker can exploit the XSS vulnerability to force a victim's browser to silently fetch their specific connection settings, extract the tokens, and exfiltrate them to an attacker-controlled webhook. Version 26.0.0 patches the issue.