The Airbrake Ruby notifier 4.2.3 for Airbrake mishandles the blacklist_keys configuration option and consequently may disclose passwords to unauthorized actors. This is fixed in 4.2.4 (also, 4.2.2 and earlier are unaffected).

The airbrake module 0.3.8 and earlier defaults to sending environment variables over HTTP. Environment variables can often times contain secret keys and other sensitive values. A malicious user could be on the same network as a regular user and intercept all the secret keys the user is sending. This goes against common best practice, which is to use HTTPS.