Joomla : Security Vulnerabilities, CVEs, Published In 2019 (Code Execution) CVSS score >= 4

In Joomla! 3.9.7 and 3.9.8, inadequate filtering allows users authorised to create custom fields to manipulate the filtering options and inject an unvalidated option. In other words, the filter attribute in subform fields allows remote code execution. This is fixed in 3.9.9.