The advanced-custom-fields (aka Elliot Condon Advanced Custom Fields) plugin before 5.7.8 for WordPress has XSS by authors.
https://www2.deloitte.com/de/de/pages/risk/articles/wordpress-plugin-xss.html
https://www.advancedcustomfields.com/changelog/
https://www.advancedcustomfields.com/blog/acf-5-7-8-release/
https://wordpress.org/plugins/advanced-custom-fields/#developers