Microsoft set to issue six critical updates

Patch Tuesday will target flaws in Word and Excel.

Microsoft has confirmed it will release six groups of security patches next week in its monthly "Patch Tuesday" release, including three critical updates for Windows and Excel users.

The vendor said these critical updates will fix bugs in many different versions of Microsoft's products including the latest versions of Excel, Windows XP, Vista and Windows Server 2003, Microsoft said in a note on its website.

Online criminals have used flaws in Excel and other Microsoft Office products in limited attacks over the past year. The attacker will typically send the victim an email containing a maliciously encoded Office attachment. If the document is opened, unauthorized software is installed that allows the hacker then gains access to the victim's computer.

Three other, less critical updates are also planned for next week's Patch Tuesday security fixes. These include "important" updates for Microsoft Publisher 2007 and Windows XP Service Pack 2, as well as a fix for Windows Vista.

But Microsoft wouldn't release any further details on the flaws Tuesday's updates will address as part of its regular, monthly set of security patches. But it usually rates an update 'critical' if it is designed to fix a vulnerability that could be used by a hacker to remotely install unauthorized software on a victim's computer.