The vulnerability could let miscreants hijack a Windows PC running IE 6 with Service Pack 1 and the MS06-042 update installed, Microsoft said in a security advisory published on Tuesday. The flaw lies in the way IE handles long Web addresses and could be exploited by luring users to specially crafted Web sites, according to the advisory.

"An attacker who successfully exploited this vulnerability could remotely take complete control of an affected system," Microsoft said in its advisory. "We are not aware of attacks that try to use the reported vulnerability."

Microsoft released the MS06-042 security update on Aug. 8 as part of its monthly patch cycle. The update, deemed "critical" by Microsoft, addresses eight flaws in the ubiquitous browser. It is one of a dozen security updates that Microsoft released this month on Patch Tuesday.

The company planned to release a new version of the MS06-042 update on Tuesday to fix a problem with browser crashes reported by some users after installing the original fix. That crash, it turns out, is the result of a "buffer overrun" flaw introduced by the security update, Microsoft said. The flaw could be exploited by cyberattackers.

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