Microsoft today said it will ship four security updates next week, only a third as many as it did last month, to fix critical vulnerabilities in Windows, Office, Windows Media Player and other parts of its software portfolio.

But just because September sports only four -- down from almost a dozen in August -- that doesn't necessarily mean patching will be a breeze, said Andrew Storms, director of security operations at nCircle Network Security.

"It's not going to be an easy month," Storms said, "what with all these different applications and different operating systems affected. Patching will be a lot more involved than you'd think with just four bulletins."

Storms called the patching job "potentially massive."

In the advance notification Microsoft published Thursday, it tagged all four of the expected updates as "critical" -- its highest threat rating. As customary, Microsoft limited the information to naming the affected software and providing only generalities about the bugs. However, all four will patch one or more "remote execution" vulnerabilities, flaws that allow attackers to gain control of a system by introducing malicious code, often by convincing users to open a file attachment or tricking them into visiting a rogue Web site.

The one bulletin labeled "Windows" actually affects more than the operating system; it also affects Internet Explorer, .Net Framework, Office, SQL Server and Visual Studio. The kitchen-sink approach to the bulletin caught Storms off-guard. "I'm confused," he admitted, and wondered whether it reflects a change in how Microsoft will outline security updates or a special case.

He leaned toward the latter. "We've had something similar, I think, and when we saw the details the next week, it all made sense," he said, of the wide range of applications and operating systems called out by that security bulletin.

Two bulletins will patch bugs in Windows' media tools. One appears to be the Windows Media Player 11 update that Microsoft originally scheduled for last month but yanked at the last minute. The second media-related update will patch an unspecified bug in Windows Media Encoder, a free Microsoft tool for converting audio and video to the Windows Media formats, or capturing live content.

Storms speculated that the two are connected. "I think it's very much tied with the Media Player update," he said, referring to the encoder patch.

The fourth bulletin will detail fixes to Office XP, Office 2003 and Office 2007 on Windows. Although many Office updates have patched file format vulnerabilities -- three last month addressed such problems in the suite, for example -- Storms didn't think that would be the case this month. "More than likely it's not a file format vulnerability, not with Office 2007 involved," he said.

Office 2007 was the first from Microsoft to use XML file formats as the default, and has proved to be more secure than older versions of the application suite.

Microsoft will also issue several non-security updates next Tuesday, including another in its series of reliability updates for Windows Vista, as well as a fix for a problem with Windows Server 2008's Hyper-V Volume Shadow Copy Service, a tool that backs up virtual machines.

The security updates and other fixes will be posted at approximately 1 p.m. EDT on Sept. 9.