
Office has been hit especially hard with new attacks in recent weeks, and still has five flaws currently unpatched.
Exploits for vulnerabilities in Excel and Word have been used to install malware on users' systems, raising concerns among security experts.
The other three 'critical' bulletins will provide fixes for vulnerabilities in Windows and Microsoft Data Access Components, as well as for Windows Live OneCare, Microsoft Antigen, Windows Defender or Microsoft ForeFront.
The company did not provide specific information on the vulnerabilities or versions of the software that will be addressed by the bulletins. Each security bulletin can contain one or more fixes for flaws in one application or software component.
Non-critical fixes for flaws in Office, Visual Studio and Step-By-Step Interactive Training will comprise the remainder of the planned security bulletins. All three have a maximum security rating of 'important'.
Along with the 12 security bulletins, this month's Patch Tuesday will include non-security updates for the Windows Malicious Software Removal Tool and several of Microsoft's software update applications.