An issue was discovered in Joomla! before 3.9.16. Inadequate handling of CSS selectors in the Protostar and Beez3 JavaScript allows XSS attacks.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-10242
Reference (s):
- https://developer.joomla.org/security-centre/803-20200302-core-xss-in-protostar-and-beez3