But none of the information Microsoft released today about the five updates or the 15 bugs was news: On Friday, the company of the security bulletins, the term Microsoft uses for the advisories that accompany each update.

All of the updates and vulnerabilities were rated "important," the second-most-serious rating in the company's four-step system.

Two of the vulnerabilities are in Windows; five are in Excel, the spreadsheet included with Office; two involve non-application Office components; and six affect SharePoint and associated software, such as Groove and Office Web Apps.

Of the 15, two are "" vulnerabilities, a term that describes a class of bugs first revealed in August 2010. Microsoft has been patching its software to fix the problem -- which can be exploited by tricking an application into loading a malicious file with the same name as a required dynamic link library, or DLL -- since last November.

Apparently that job isn't finished: Microsoft has yet to close a 2010 advisory that warns users of DLL load hijacking bugs in the company's software.