2008/03/01 Most of you have probably seen Fail2ban taking a lot of CPU and disk access on February 29th. We already fixed it and I will release 0.8.2 (which has nice new features) as soon as possible but in the meanwhile, please patch Fail2ban yourself. You will find a patch here. It's Python so no need to compile anything.
2007/08/14 0.8.1 is now available and fixes some security issues in the default configuration files and includes new filters and actions. The "mail" actions are now deprecated and should be replaced with "sendmail" actions. fail2ban-regex now accepts "ignoreregex".
2007/06/07 Daniel B. Cid wrote an article about Attacking Log analysis tools. There is a section that points out a vulnerability in Fail2ban. I strongly recommend that you apply the patch provided in the article. A few weeks ago, Yaroslav Halchenko wrote an article about Fail2ban for Debian Package of the Day.