The updates are aimed at correcting critical security vulnerabilities in the previous version, which could be used by a malicious attacker to gain control of affected systems. The exploits relate to three specific file formats opened by Photoshop -- ASL (Photoshop Style), .ABR (Photoshop Brushes), and .GRD (Photoshop Gradient). In addition, the updates correct various unspecified problems with brushes, styles and gradient presets for both Windows and Macintosh users.
Adobe Photoshop CS5 is said to be unaffected by these issues. The updates to Photoshop CS4 v11.0.2 are available immediately from Adobe's Windows and Macintosh download pages.