Sulu is an open-source PHP content management system based on the Symfony framework. In versions before 1.6.43 are subject to stored cross site scripting attacks. HTML input into Tag names is not properly sanitized. Only admin users are allowed to create tags. Users are advised to upgrade.
https://github.com/sulu/sulu/security/advisories/GHSA-h58v-g3q6-q9fx
https://github.com/sulu/sulu/commit/20007ac70a3af3c9e53a6acb0ef8794b65642445