I agree with Tedster. The report seems a little unscientific, or at the very least, that article is a little unscientific (I don't know the severity of the flaws because that article failed to link to the actual report). I would not be surprised to learn that Chrome had a higher than average number of vulnerabilities, given how relatively new it is (though that doesn't prevent me from using it as my default browser), I just wish that article gave more details.
Interesting to note, the browser that everyone loves to pick on (with regards to security) is IE, which falls in at only 8th place, well below the vulnerabilities in competing browsers Chrome, Safari, and Firefox. But again, without knowing what those vulnerabilities are, this article is rather useless.