Emlog is an open source website building system. In versions 2.5.21 and below, an HTML template injection allows stored cross‑site scripting (XSS) via the mail template settings. Once a malicious payload is saved, any subsequent visit to the settings page in an authenticated admin context will execute attacker‑controlled JavaScript, enabling session/token theft and full admin account takeover. This issue is fixed in version 2.5.22.