This would be a cool service to integrate with github badges, next to test coverage and build status. e.g. "2 UNPATCHED VULNERABILITIES" or "VULNERABILITY ASSESSMENT PASSED"

It should be simple enough to intersect the list of a project's dependencies with a list of libraries with known vulnerabilities.

If you provided this as a free service, you'd get a bunch of free advertising from the github badges, like travis-CI. :)