PhpGedView is prone to a cross-site scripting vulnerability. Remote attackers may create malicious links to this script that include hostile HTML and script code. If such a link was followed by a victim user, the attacker-supplied code would be rendered in the security context of the site hosting the software.
This could be exploited to steal cookie-based authentication credentials. Other attacks are also possible.
This issue is reported to affect PhpGedView 2.61. Other versions are also likely affected.