An Argentinian security researcher, Juan Pablo Lopez Yacubian, has discovered two vulnerabilities in Apple's Safari browser for Windows.
The two flaws can allow criminals to take over the targeted computer remotely.
The first one presents a legitimate URL address and then redirecting the user to another, compromised webpage which can contain malware that can then infect your computer.
The second flaw happens when a user downloads a file with a very long filename which can then be used by a hacker to cause a memory corruption, which can then be used to take over the victim's machine.
At the time of writing, both vulnerabilities were unpatched and security firm Secunia has given a highly critical status to both vulnerabilities.
The flaws were found in Safari v3.1 although other versions could potentially be at risks.
It is also not known whether Mac versions of Safari could be affected by the two flaws.
Safari has already been hit by a number of security warnings since it was released in 2003.
Its Windows version, released in 2007, contained a security vulnerability which was dug up a few hours after its release.