CFForm issue in CF11

We found an issue related to the FORM submission in CF11. If the action attribute is not specified in the cfform tag, it does not generate the action using the current URL(Query-string values containing specific text are getting truncated ) .

For example :

sample URL :  http://test.com/admin/index.cfm?page=test&prod=12 , in the given URL having the value 'prod' , after submiting this form  , this URL will be showed like this - http://test.com/admin/index.cfm? with out query string values.

How can we resolve this issue in CF11 . Please advise.

Thanks in advance