Online attack code has been released targeting a critical, unpatched flaw in the Firefox browser.

The attack code, written by security researcher Guido Landi was published on several security sites Wednesday, sending Firefox developers scrambling to patch the issue. Until the flaw is patched, this code could be modified by attackers and used to sneak unauthorized software onto a Firefox user's machine.

Mozilla developers have already worked out a fix for the vulnerability. It's slated to ship in the upcoming 3.0.8 release of the browser, which developers are now characterizing as a "high-priority firedrill security update," thanks to the attack code. That update is expected sometime early next week.

Firefox 3.0.8 is a high-priority firedrill security update to Firefox 3.0.x.