Secunia’s Vulnerability Report for Mozilla Firefox 1.x shows seven advisories for 2005, making a total of 11 since the browser was officially released last November. Three of the 11 issues (27%) are unpatched, and five are shown as partially fixed.
In the same period of time, Secunia has issued 15 advisories for Internet Explorer 6, five of them in 2005. According to Secunia, 32% of all current IE6 advisories are unpatched.
Interesting reading.
Ed Bott 
It is interesting reading. It makes me cringe when I see people saying “Firefox is secure” – it isn’t. It is, however, apparently more secure than IE – one thing your article did not mention was the overall rating that Secunia gave IE and Firefox. Secunia currently rates Firefox as ‘less critical’, but IE as ‘highly critical’, due to some unpatched flaws that have been known for some time now.
Of course, for all we know someone could find a stonkingly huge flaw in Firefox tomorrow and the balance would change entirely. But as it stands, Firefox is the more secure browser.
Actually, that’s NOT an “overall rating” of browser security. It is an indicator that shows the rating of the most severe unpatched vulnerability, as defined by Secunia. On the five-bars scale, Microsoft has at least one unpatched vulnerability that is at three bars, while the worst Firefox bug is at two bars. And if you look at the IE vulnerability in question, you see it’s a pretty obscure bug that would require a specially crafted local share, and which Microsoft says is fixed.
In general, I agree that using Firefox will keep the average user more secure. But is is NOT a panacea.