Adobe will fix security bug in CS5.x having originally said CS6 was the fix
Photo Issues
Adobe has confirmed that it will fix the security problems with Photoshop and other CS5.x packages, having originally suggested that a paid upgrade to CS6 was the only solution. The security concerns, raised by the company on May 8th, were rated as 'critical,' meaning it could 'allow malicious native-code to execute, potentially without a user being aware.' Despite this, the original solution raised in the company security bulletin was to upgrade to CS6, leaving CS5.x users vulnerable. The bulletin has now been updated.
Source: News: Digital Photography Review (dpreview.com)