(See important update below for information on patching this vulnerability).
Heads up for Windows users: There's a critical, remotely exploitable vulnerability in Adobe Acrobat/Reader version 8.
According to an advisory from Core Security, Adobe Reader suffers from a stack buffer overflow when parsing specially crafted (invalid) PDF files. The flaw could be exploited if a user is tricked into opening a rigged PDF file, the company warned.
From the alert:
Vulnerable versions: Adobe Reader 8.1.2 and Adobe Acrobat 8.1.2.