Cross-site scripting (XSS) vulnerability in Simple Email Form 1.8.5 and earlier allows remote attackers to inject arbitrary web script or HTML via the mod_simpleemailform_field2_1 parameter to index.php.
https://www.htbridge.com/advisory/HTB23241
http://www.securityfocus.com/bid/71131
http://www.securityfocus.com/archive/1/534017/100/0/threaded