This indicates an attack attempt against a Cross Site Scripting vulnerability in Microsoft Internet Explorer.
The vulnerability is caused by an error where the browser fails to properly sanitize the argument of a "res: URI" sent to "navcancl.htm". An attacker may include malicious script code by supplying an injection string through the URL.
Microsoft Internet Explorer 7.
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the patch supplied by the vendor.