- XSS: normalize notification values (Amount, Payer, AccountNo, Status) before writing to payment fields. The Payer field is escaped using htmlspecialcharsbx(), and the Amount field is converted to a number using number_format().
- Auth Bypass: notification signature verification is now mandatory (fail-closed). The signature is always checked, regardless of settings. The secure default is EPOS_IS_USE_SIGNATURE_FROM_NOTIFICATION = Y.
- An administrator warning has been added when signature verification is disabled.
- All accesses to notification data now use isset()/?? with type casting (eliminates PHP warnings in PHP 8).
- Logging of all accepted and rejected notifications.
- Notification address substitution: the HTTP_HOST fallback has been removed when forming the default notification address; the host is taken only from server_name, the protocol is always HTTPS, and if server_name is empty, no address is set.