By identifying bugs so efficiently, Holley writes that AI tools like Mythos tilt the cybersecurity balance toward defenders, who benefit when discovering vulnerabilities becomes cheaper for both sides. “Computers were completely incapable of doing this a few months ago, and now they excel at it,” Holley writes. “We have many years of experience picking apart the work of the world’s best security researchers, and Mythos Preview is every bit as capable.”

In an interview with Wired, Holley said that, from now on, this kind of AI-aided vulnerability analysis is something that “every piece of software is going to have to [engage with], because every piece of software has a lot of bugs buried underneath the surface that are now discoverable.” And while it’s possible that future models more advanced than Mythos may be able to find bugs that current models miss, Holley said he was confident that “at least on the Firefox side, having had a bit of a head start here, that we’ve rounded the curve.”

Running through the AI-aided defense gauntlet could be especially important for the open source projects that underpin much of the modern Internet. That’s both because their public codebases are easier for AI systems to explore for vulnerabilities and because many such projects rely on wildly insufficient volunteer maintenance for their security.

In a New York Times essay last week, Mozilla CTO Raffi Krikorian argued that the human difficulty of both finding bugs and writing complex software has created a kind of balance in cyberthreat research that Mythos could break wide open. “The programmer who gave 20 years of his life to maintain [open source] code that runs inside products used by billions of people? He doesn’t have access to Mythos yet. He should,” Krikorian wrote.