The LatePoint plugin for WordPress is vulnerable to Stored Cross-Site Scripting in all versions up to and including 5.5.0. This is due to insufficient input sanitization on the customer cabinet profile update endpoint, where raw POST parameters (first_name, last_name, phone, notes) bypass sanitization because OsCustomerModel does not override params_to_sanitize(), causing set_data() to store unsanitized values verbatim in the database, combined with insufficient output escaping in generate_preview(), which injects those stored values into notification template HTML via str_replace() without any esc_html() call before echoing the result. This makes it possible for authenticated attackers with customer-level access or above to inject arbitrary web scripts into the admin notification preview panel that execute in an administrator's or agent's browser whenever a notification template referencing customer variables such as {{customer_full_name}}, {{customer_first_name}}, {{customer_last_name}}, {{customer_phone}}, or {{customer_notes}} is previewed.