Adobe has released security updates for Adobe Reader and Acrobat XI for Windows and Macintosh. These updates address critical vulnerabilities that could potentially allow an attacker to take control of the affected system.

Update checks can be manually activated by choosing Help > Check for Updates.
Adobe Reader XI (11.0.19, Pro and Standard) for Windows is available here: Adobe - Adobe Reader : For Windows : Adobe Reader 11.0.18 update - All languages.Reader DC and other versions are available here: Adobe - Adobe Reader : For Windows.Acrobat for Windows update is available here: Adobe - Acrobat : For Windows

Note: UNcheck any pre-checked additional options presented with the update. They are not part of the software update and are completely optional.

Release Notes | Acrobat, Reader
Security Bulletin