In Joomla! 1.5.0 through 3.6.5 (fixed in 3.7.0), inadequate filtering of multibyte characters leads to XSS vulnerabilities in various components.
https://fortiguard.com/zeroday/FG-VD-17-109
https://fortiguard.com/zeroday/FG-VD-17-108
https://fortiguard.com/zeroday/FG-VD-17-107
https://developer.joomla.org/security-centre/685-20170403-core-xss-vulnerability