Microsoft is only issuing four bulletins for Patch Tuesday this month, but it will fix a hefty 22 vulnerabilities. Three bulletins update Windows, the fouth addresses a number of flaws in Visio 2003.
One of the Windows bulletins is ranked "critical," with the remainder all merely "important." Unusually, the critical bulletin is only applicable to Windows Vista and Windows 7; Windows XP and the server operating systems won't need it. The critical Windows bulletin and the Office update both fix remote code execution issues; the other two Windows fixes resolve elevation of privilege flaws. All three Windows updates need a reboot to apply, though the Visio one should not.