Coppermine Photo Gallery (CPG) 1.4.8 stable, with register_globals enabled, allows remote attackers to bypass XSS protection and set arbitrary variables via a query string that causes the variable to be defined in global space, with separate _GET, _REQUEST, or other critical parameters, which are unset by the protection scheme and prevent the original variable from being detected.
https://exchange.xforce.ibmcloud.com/vulnerabilities/27376
http://svn.sourceforge.net/viewvc/coppermine?view=rev&revision=3133
http://securityreason.com/securityalert/1914
http://secunia.com/advisories/20597
http://archives.neohapsis.com/archives/bugtraq/2006-06/0482.html