Tuleap is an Open Source Suite to improve management of software developments and collaboration. Users are able to see backlog items that they should not see. This issue has been patched in Tuleap Community Edition version 15.9.99.97.
https://tuleap.net/plugins/tracker/?aid=38297
https://github.com/Enalean/tuleap/security/advisories/GHSA-4c9f-284j-phvj
https://github.com/Enalean/tuleap/commit/13eec93a353d2daf47bb8b9c548cc02f78b93a5e