Cross-site scripting (XSS) vulnerability in header.php in PHP-Nuke 6.0 to 7.8 allows remote attackers to inject arbitrary web script or HTML via the pagetitle parameter.

Interpretation conflict in includes/mainfile.php in PHP-Nuke 7.9 and later allows remote attackers to perform cross-site scripting (XSS) attacks by replacing the ">" in the tag with a "<", which bypasses the regular expressions that sanitize the data, but is automatically corrected by many web browsers. NOTE: it could be argued that this vulnerability is due to a design limitation of many web browsers; if so, then this should not be treated as a vulnerability in PHP-Nuke.