Microsoft is planning a bumper patch Tuesday, with 13 bulletins that collectively fix 26 difference vulnerabilities.

Five of the bulletins are rated critical, seven as important, and one as moderate risk. Eleven of the baker's dozen of notices affect Windows, while two involve Office.

All versions of Windows will need patching, but Win XP and 2000 users (with five critical bulletins to consider) have more to worry them than Vista and Win 7 users (with each OS getting three critical updates).

Microsoft has recently started using a patch chart which provides a neat summary of what's in store next Tuesday, without going into details, here. The batch of fixes will not include a patch for a recently discovered bug in Internet Explorer that potentially allows hackers to browse files on vulnerable machines, a vulnerability demonstrated at the Black Hat conference in Washington earlier this week. ®