One of the critical vulnerabilities is being used in attacks against Reader and Acrobat; the other, fixed in an emergency update late last month, targets Flash Player.
The updates affect Adobe Reader 9.3.4 for Windows, Macintosh, and Unix; Adobe Acrobat 9.3.4 for Windows and Macintosh; and Adobe Reader 8.2.4 and Acrobat 8.2.4 for Windows and Macintosh to resolve issues in Reader, Acrobat, and Flash Player. Details are in the latest security advisory.
The next quarterly security updates for Adobe Reader and Acrobat are scheduled for February 8, 2011.