If you would like to report a bug, please take a look at our Redmine issue tracker -- your bug may already have been reported there! Simply searching for some appropriate keywords may save everyone a lot of hassle.
If your bug is new and you'd like to report it you will need to register first. Don't worry, it's easy and fun and takes about 30 seconds.
When you file a bug report, please inclue your steps to reproduce, full copy-pastes of Ruby stack traces, and any relevant details about your environment. Without repro steps, your bug will likely be closed. With repro steps, your bugs will likely be fixed.
If you have an exploit that you'd like to contribute to the Metasploit Framework, please familiarize yourself with the HACKING document in the Metasploit-Framework repository. There are many mysteries revealed in HACKING concerning code style and content.
Pull requests should corellate with modules at a 1:1 ratio -- there is rarely a good reason to have two, three, or ten modules on one pull request, as this dramatically increases the review time required to land (commit) any of those modules.
Pull requests tend to be very collaborative for Metasploit -- do not be surprised if your pull request to rapid7/metasploit-framework triggers a pull request back to your own fork. In this way, we can isolate working changes before landing your PR to the Metasploit master branch.