Microsoft has issued a patch for an Internet Explorer zero-day flaw being actively exploited by malicious hackers and that was first identified Saturday .

The flaw, which affects IE 6 through IE 11, could allow attackers to execute code remotely on a compromised computer if the user views an infected webpage using the browser.

“An attacker who successfully exploited this vulnerability could gain the same user rights as the current user,” reads the security bulletin.

The flaw is rated Critical, the most severe rating in Microsoft’s security categories.

The patch will be automatically downloaded and installed in Windows computers configured to receive software updates from Microsoft. Users who don’t get these automatic updates are advised to install this patch manually right away.

Although Windows XP users aren’t supposed to get this type of patch delivered to them anymore, since support for the OS ended on April 8, Microsoft is making an exception and pushing out this update to them as well.

“The security of our products is something we take incredibly seriously. When we saw the first reports about this vulnerability we decided to fix it, fix it fast, and fix it for all our customers,” Adrienne Hall, general manager, Microsoft Trustworthy Computing, said in a statement.

The most likely scenario for victimizing users with this flaw is the distribution by attackers via email and IM messages of links to malicious websites.

PCWorld