Comment 11 for bug 133569

Do you have any configuration entries defined which match REGEX? If not, I
believe this is a known upstream bug. My understanding, however, is that it is
harmless; ssh doesn't provide a hostname in that message so there is no way to
extract a hostname to block from it, and the message you see in your logs is
informing you of that. I am not sure that ssh actually provides the messages
necessary to do what you are attempting to do, although please include it if so.
 Otherwise I don't see that the underlying problem is something that can be
solved with denyhosts.

http://<email address hidden>/msg00132.html

Note also that there was no upstream response to this; in fact, upstream seems
to have gone dormant. If you have other suggestions on how we could make minor
modifications to the denyhosts packaging to accommodate this, I'm happy to hear
them. But my feeling now is that in the absense of additional messages from
openssh which aren't being considered, this is not a denyhosts bug.