Tuleap is an Open Source Suite to improve management of software developments and collaboration. Some users might get access to restricted information when a process validates the permissions of multiple users (e.g. mail notifications). This issue has been patched in version 15.4.99.140 of Tuleap Community Edition.
https://tuleap.net/plugins/tracker/?aid=35862
https://github.com/Enalean/tuleap/security/advisories/GHSA-m3v5-2j5q-x85w
https://github.com/Enalean/tuleap/commit/0329e21d268510bc00fed707406103edabf10e42