Cacti through 1.2.7 is affected by multiple instances of lib/functions.php unsafe deserialization of user-controlled data to populate arrays. An authenticated attacker could use this to influence object data values and control actions taken by Cacti or potentially cause memory corruption in the PHP module.
In Cacti through 1.2.6, authenticated users may bypass authorization checks (for viewing a graph) via a direct graph_json.php request with a modified local_graph_id parameter.
In clearFilter() in utilities.php in Cacti before 1.2.3, no escaping occurs before printing out the value of the SNMP community string (SNMP Options) in the View poller cache, leading to XSS.