LeptonCMS version 7.3.0 contains an arbitrary file upload vulnerability, which is caused by the lack of proper validation for uploaded files. An authenticated attacker can exploit this vulnerability by uploading a specially crafted ZIP/PHP file to execute arbitrary code.

An XSS vulnerability exists in modules/wysiwyg/save.php of LeptonCMS 4.5.0. This can be exploited because the only security measure used against XSS is the stripping of SCRIPT elements. A malicious actor can use HTML event handlers to run JavaScript instead of using SCRIPT elements.