Security test is failing with error. : [Cross Site Scripting] Request 10 - FAILED: took 27 second

You are probably looking for Response SLA assertion. Click the Response Assertions button and find the Response SLA assertion in the editor on the right. Then double-click the assertion and set the timeout in milliseconds.

Also note that Secure runs SoapUI NG tests and the assertion might be in the SoapUI NG test step you run. This can also fail the test.