OpenSSH has its own Bugzilla instance.
The primary Debian maintainer of OpenSSH is also an Ubuntu developer, so many bugs are filed in Debian too.
Using the bug tracker
OpenSSH bugs are tracked upstream at bugzilla.mindrot.org. Click 'New Account' at the top and enter your email address.
As with other Bugzilla instances.
Filing new bugs
Check if the bug is already reported with the search tool
If it doesn't already exist open a new bug
After this just submit the bug and follow the steps listed here for linking the report to Launchpad.
Launchpad Bug Watch
After you have forwarded the bug to OpenSSH's bugzilla you will want to create a "Bug Watch" in Launchpad that links the Ubuntu bug to the OpenSSH bug. This bug watch will be updated regularly and reflect the status of the upstream bug report. Details on creating one are found at Bugs/Watches.
Patches should be created against the current git repository. To check this out:
git clone https://anongit.mindrot.org/openssh.git
Be extremely wary of creating new configuration options without forwarding them upstream. It is not uncommon for upstream to select a different name during the process of agreeing on the patch, and if the option was previously added to distribution packaging then we can end up having to maintain compatibility code forever.