One of the critical flaws addressed allows IE 10 to be exploited by attack code placed on compromised Web sites.
Microsoft's corporate vice president of Internet Explorer, Dean Hachamovitch, is taking on a new job at the company.
Following the release of Internet Explorer 11, Google Apps says sayonara to IE 9.
StatCounter browser data agrees with Net Applications' earlier findings that Internet Explorer is on the rise.
Use of the browser has surged since Microsoft unveiled a version for Windows 7 in November, according to data from Net Applications.
It may be a turnaround or it may be a blip, but Internet Explorer's share of usage resumed growth according to separate studies of the Web.
Internet Explorer 11 saw a gain of almost two percentage points in all desktop browser traffic recorded by Net Applications in November.
Sauce Labs' 55 million tests of Web pages and apps find Microsoft's browser the most crash-prone, but IE10's error rate is a sixth that of IE6.
On Patch Tuesday, Microsoft gives IT admins a heads-up on eight updates that address 23 vulnerabilities spread among Internet Explorer, Exchange, and Windows.
Belfiore will add Internet Explorer to his list of duties. He replaces Dean Hachamovitch, who says he's starting a new team at Microsoft.