Drupal 6.1, a maintenance release that fixes problems reported using the bug tracking system, as well as security vulnerabilities is now available for download. The security issues identified were in code new to Drupal 6, and are therefore not applicable to sites running on Drupal 5.
Upgrading your existing Drupal 6 sites is strongly recommended. There are no new features in this release. For more information about the Drupal 6.x release series, consult the Drupal 6.0 release announcement.
We have a security announcement mailing list, a history of all security advisories, and an RSS feed with the most recent security advisories. We strongly advise Drupal administrators to sign up for the list.
Drupal 6 also includes the Update status module built-in, which informs you about important updates to your modules and themes.
The full list of changes between the 6.0 and 6.1 releases can be found by reading the 6.1 release notes. A complete list of all bug fixes in the stable DRUPAL-6 branch can be found at http://drupal.org/project/cvs/3060/?branch=DRUPAL-6.
Drupal 6.1 was released in response to the discovery of potential security vulnerabilities. Details can be found in the official security advisory:
To fix the security problems, you can either (1) upgrade Drupal or (2) patch Drupal.
We recommend you do the full upgrade as the patches do not contain the additional bugfixes that went into the release. Applying the patches will leave your site in an unversioned state, confusing update status module, which will keep reminding you to upgrade to 6.1; but your site will at least be secure.
If you still prefer to patch Drupal, apply the http://drupal.org/files/sa-2008-018/SA-2008-018-6.0.patch file to your code base.