CometD is a scalable comet implementation for web messaging. In any version prior to 5.0.11, 6.0.6, and 7.0.6, internal usage of Oort and Seti channels is improperly authorized, so any remote user could subscribe and publish to those channels. By subscribing to those channels, a remote user may be able to watch cluster-internal traffic that contains other users' (possibly sensitive) data. By publishing to those channels, a remote user may be able to create/modify/delete other user's data and modify the cluster structure. A fix is available in versions 5.0.11, 6.0.6, and 7.0.6. As a workaround, install a custom `SecurityPolicy` that forbids subscription and publishing to remote, non-Oort, sessions on Oort and Seti channels.