Concrete CMS (formerly concrete5) below 8.5.10 and between 9.0.0 and 9.1.2 is vulnerable to XXE based DNS requests leading to IP disclosure.
https://www.concretecms.org/about/project-news/security/concrete-cms-security-advisory-2022-10-31
https://github.com/concretecms/concretecms/releases/9.1.3
https://github.com/concretecms/concretecms/releases/8.5.10
https://documentation.concretecms.org/developers/introduction/version-history/913-release-notes
https://documentation.concretecms.org/developers/introduction/version-history/8510-release-notes