This isn't a Mac-specific story, but it is highly relevant to Mac users that have found they can't rely 100% on Preview's ability to display PDF files.

Adobe has already released the security updates for Reader and Acrobat that were scheduled to appear on July 13. The company's quarterly release schedule that would normally fall on the second Tuesday of every third month, in part to align with Microsoft's monthly schedule.

But Adobe has made it clear that the quarterly schedule will be ignored when it's necessary to provide protection against real-world threats. And that's what apparently happened this time.

One of the fixes in Reader and Acrobat blocks by default attempts to launch executables or other harmful objects contained in a PDF file. Back in March, a security researcher showed how the text of a warning dialog could be modified to encourage users to allow their launch, and Adobe has also changed that dialog to make it harder to trick users.

Another mirrors a recent change to Flash to remove a vulnerability that might allow an attacker to take control of a system.

So if you haven't already updated to Reader or Acrobat 9.3.3 (or 8.2.3 if you've had to stay with the old major version for some reason), it's probably worth doing so.