CVE-2021-26035
An issue was discovered in Joomla! 3.0.0 through 3.9.27. Inadequate escaping in the rules field of the JForm API leads to a XSS vulnerability.
Date published : 2021-07-07
https://developer.joomla.org/security-centre/856-20210701-core-xss-in-jform-rules-field.html