Language: PHP
Label: safe
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:
    protected function _findUnused($hash)
    {
        $accessed = $hash->getAccessed();
        foreach ($hash as $k => $v) {
            if (!isset($accessed[$k])) {
                trigger_error("String hash key '$k' not used by builder", E_USER_NOTICE);
            }
        }
    }