Shopware is an open source eCommerce platform. Versions prior to 5.6.10 suffer from an authenticated stored XSS in administration vulnerability. Users are recommend to update to the version 5.6.10. You can get the update to 5.6.10 regularly via the Auto-Updater or directly via the download overview.
https://github.com/shopware/shopware/security/advisories/GHSA-f6p7-8xfw-fjqq
https://github.com/shopware/shopware/commit/a0850ffbc6f581a8eb8425cc2bf77a0715e21e12
https://docs.shopware.com/en/shopware-5-en/security-updates/security-update-05-2021