I was recently doing some research with regard to a customer's version of ColdFusion and thought that this would be helpful. Adobe keeps a chart of the versions of ColdFusion at this link.
Why is this important you may ask? Well, as in every software package there are patches and updates that come on-line as the product matures. In past cases there have been versions of CF which have had issues that a patch or update resolved. With any update it is important to conduct preliminary tests of your current environment with the update in a test or staging area to resolve any issues that might arise, though it is rare to see an updater to CF result in an unstable machine.
To locate the version of CF that you currently have installed, open the CF administrator and browse to Settings Summary. You will see version information at the top of the screen output. It will look something like this: