WordPress 2.8.4 has been released. It’s a security release, which means you should upgrade immediately. This version fixes a problem that could allow remote users to reset the administrative password. Below is a summary from the WordPress development blog:
Yesterday a vulnerability was discovered: a specially crafted URL could be requested that would allow an attacker to bypass a security check to verify a user requested a password reset. As a result, the first account without a key in the database (usually the admin account) would have its password reset and a new password would be emailed to the account owner. This doesn’t allow remote access, but it is very annoying.