Microsoft will push out seven software updates tomorrow (March 12) for this month's Patch Tuesday. Four are rated "critical" and will patch severe security flaws, including one that affects Mac OS X.
Microsoft defines "critical" flaws as those that allow remote code execution, which could let a hacker take over your computer without warning.
The first critical patch, as detailed on Microsoft's posted advance notice, affects all supported versions of Windows (Windows XP through Windows 8) and all supported versions of Internet Explorer. It is rated a "moderate" threat for Windows Server 2003, 2008 and 2012.
"Bulletin 1 will be on the top of our list next week," wrote Wolfgang Kandek, chief technology officer of Redwood Shores, Calif., vulnerability-management firm Qualys, on the company blog. "It fixes critical vulnerabilities that could be used for machine takeover in all versions of Internet Explorer, from 6 to 10, on all platforms including Windows 8 and Windows RT."
Bulletin 2 fixes a remote-execution flaw in Silverlight, Microsoft's multimedia platform used by video-streaming services such as Netflix.
The remote-execution flaw affects both Windows machines and Macs with Silverlight installed. If you watch Netflix on a PC or Mac (and possibly a Linux machine as well), you'll need this patch.
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Bulletin 3 patches a critical hole in Microsoft Office 2010 for Windows, as well as the 2010 edition of the Visio diagramming software. Microsoft Office 2013 isn't affected.
The fourth critical bulletin affects the 2010 edition of Microsoft SharePoint, a business document-management platform.
Microsoft rated bulletins 5 through 7 as "important," meaning compromises can't occur without user permission. The updates affect all supported versions of Windows, the 2010 edition of the collaborative software OneNote and the 2008 and 2011 editions of Microsoft Office for Mac.
This week's patches are part of Microsoft's regular schedule of security and software updates, which are released on the second Tuesday of each month.
Updates will be pushed out to users tomorrow at 2:00 p.m. ET.