I just want to say I think it is cool the OP tries to make FD aware of any potential exploit without revealing it here. I am pretty sure loads of folks would have just took the ball and ran.
Well, there's a point to spilling the beans. If it is broadcast on the forums AND to every CMDR the OP encounters, it'll be picked up quick by lots of people.
And we know what happens when lots of people start taking advantage of unintended exploits. FD comes down HARD AND FAST. Look no further than "seeking luxuries" or the recent smuggling missions. Having the "I've got a secret" means it generally stays around for a good while, until it reaches enough mass to show up on the dev's radar.
I personally don't like exploits, even the minor ones, such as logging into solo/group/open modes to get the bulletin board to generate messages, or quick ranking by exploiting the charity missions. And yes, if you've got a good one, definitely let the devs know, but let them know it's serious, as the entire forum population is about to start using said exploit.
As far as repercussions, they don't ban folks for using a game mechanic (no matter how mis-coded it might be).