When I try to file new bugs using GLSAMaker API I am getting "Internal Server Errors" for more than a week now. Because I don't have access to logs I can't provide any more details.
It seems that I've managed to fix it. Long story short, this got broken due to the system upgrading to Ruby 2.4. I've regenerated the bundle for Ruby 2.4, then had to upgrade Rails to version that works with Ruby 2.4, then fix some missing dep or whatever, then had to get a fresh API token out of Bugzilla.