Microsoft will issue a patch to fix security issues with its Internet Explorer 7 browser.

The emergency update is due to be available from 6pm on 17 December and is marked as "critical", Microsoft's most urgent level in its four step system.

The security flaw is believed to have affected as many as 10,000 websites and can see cyber-crims steal PC user's passwords and other information.

The issue was considered so serious by some security experts that they have recommended people switch browsers until the problem is addressed, although no browser is 100% safe.