In all currently supported Windows operating systems a security vulnerability in the so-called MHTML handler can lead to information disclosure; speculations in the media indicate possibly even worse things. The cyber criminals just need a manipulated link to trigger the flaw, for example within an email or with a web page. Microsoft released a security advisory about the issue and announces an update to fix the vulnerability.
To secure the own computer, the company also provides a Fix-it tool as workaround which disables the MHTML handler. This will render attacks useless. Thus it is advised to apply the workaround by downloading and executing the Fix-it tool as soon as possible.