OpenMage magento-lts before 20.18.2 and 21.0.0-beta1 before 21.0.0-beta3 contains an information disclosure vulnerability in Mage_Rss_Model_Resource_Order::getAllCommentCollection(), which omits the is_visible_on_front filter for invoice, shipment and credit-memo comments. Authenticated customers can open the /rss/order/status feed for their order to read internal staff comments, such as fraud-review and payment notes.