libyaml vulnerability

[Tobias Pfeiffer]

Here is a summary of the libyaml vulnerability mentioned yesterday and
how to mitigate it:
https://groups.google.com/forum/#!topic/rubysec-announce/3sx25iR7yHQ

Cheers,
Tobi

[Mathias Meyer]

If your apps run on Heroku (like ours), all that's required is a new push, and their deployment will use the updated versions of MRI. See https://devcenter.heroku.com/changelog-items/423

Cheers, Mathias