Language: JavaScript
Label: vulnerable
CWE: CWE-79 \u2014 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Code:
    function renderWarning(node) {
        var gui = '';
        if (node.message) {
            gui += '<div class="warning"><span>' + node.message + '</span></div>';
        }
        return gui;
    }