Except from their website:

A critical vulnerability has been identified in Adobe Reader X (10.1.1) and earlier versions for Windows and Macintosh, Adobe Reader 9.4.6 and earlier 9.x versions for UNIX, and Adobe Acrobat X (10.1.1) and earlier versions for Windows and Macintosh. This vulnerability (CVE-2011-2462) could cause a crash and potentially allow an attacker to take control of the affected system. There are reports that the vulnerability is being actively exploited in limited, targeted attacks in the wild against Adobe Reader 9.x on Windows.

We are in the process of finalizing a fix for the issue and expect to make available an update for Adobe Reader 9.x and Acrobat 9.x for Windows on December 16, 2011. Because Adobe Reader X Protected Mode and Adobe Acrobat X Protected View would prevent an exploit of this kind from executing, we are currently planning to address this issue in Adobe Reader X and Acrobat X for Windows with the next quarterly security update for Adobe Reader and Acrobat, currently scheduled for January 10, 2012. We are planning to address this issue in Adobe Reader and Acrobat X and earlier versions for Macintosh as part of the next quarterly update scheduled for January 10, 2012. An update to address this issue in Adobe Reader 9.x for UNIX is planned for January 10, 2012. For further context on this schedule, please see the corresponding ASSET blog post.

Looks like we'll be patching Adobe Reader and Acrobat tomorrow against this newest threat that has been making the rounds over the past couple weeks.  

-- Joel Esler | http://blog.joelesler.net | http://twitter.com/joelesler