The WordPress team just released a new version of WordPress (3.1.2) to fix a security issue where contributor-level users were allowed to publish posts. The issue was discovered by a member of our security team, WordPress developer Andrew Nacin, with Benjamin Balter. This release also fixes a few bugs that missed the boat for version 3.1. It is a small release, and everyone using WordPress should upgrade to it! The release is a security release for all previous WordPress versions.
Source: https://thehackernews.com/2011/04/wordpress-312-released-security-fixes.html