AI code security with Claude Mythos Preview: Inside Tenable’s 500+ hours of testing for Project Glasswing

We spent 500+ hours and 40 billion tokens testing Anthropic’s Claude Mythos Preview for Project Glasswing. The takeaway: frontier AI won't run your code security program, but used well, it can make one even stronger.Key takeawaysFrontier AI dramatically scales security testing. In one month, Tenable dedicated 11 security experts and more than 40 billion tokens testing Claude Mythos Preview across source code analysis, exploit creation, binary reverse engineering, threat modeling, and dynamic testing. Human expertise turns frontier AI findings into real risk reduction. More findings don't automatically mean more risk. Mythos Preview surfaced a high volume of findings, but only a fraction proved to be true exposures once Tenable experts determined their reachability, exploitability, and whether existing controls already mitigated them. Source code access is the defender's asymmetric advantage. Frontier AI is far more powerful when it can read the full source, and that visibility is something defenders have and outside attackers don't. Securing code repositories is more important than ever. Ever since Anthropic introduced Claude Mythos Preview, the security community has been buzzing…