The critical bulletin apples only to Windows 7 and Vista, and involves one or more vulnerabilities that can lead to remote code execution.
Two bulletins rated important affect Windows 7, Vista, XP, Server 2008 and Server 2003.
The remaining bulletin describes an important vulnerability in Visio 2003.
Microsoft also plans to release updated versions of the Malicious Software Removal Tool and the Windows Mail Junk E-mail Filter, plus non-security updates for Windows 7, Windows Embedded Standard 7, Vista, Server 2008 R2 and Server 2008.
The updates are scheduled for release on July 12 at 10am US PDT.