Yestarday we informed of extremely critical flaws in Adobe Reader and Acrobat. Today a highly critical vulnerability was reported in Flash Player. It is due to an unspecified error. The flaw allows attacker to execute arbitrary code and compromise user’s system.
The vulnerability was found in version 11.1.102.55. Other versions may also be vulnerable.
Flash Player users should not visit untrusted websites.

Source: Secunia
08.12.2011