Tuleap is an Open Source Suite to improve management of software developments and collaboration. Tuleap does not enforce read permissions on parent trackers in the REST API. This vulnerability is fixed in Tuleap Community Edition 16.5.99.1742392651 and Tuleap Enterprise Edition 16.5-5 and 16.4-8.
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.