Automated AI vulnerability discovery is reversing the enterprise security costs that traditionally favour attackers. Bringing exploits to zero was once viewed as an unrealistic goal. The prevailing operational doctrine aimed to make attacks so expensive that only adversaries with functionally unlimited budgets could afford them, thereby disincentivising casual use. However, the recent evaluation by the Mozilla Firefox engineering team – using Anthropic’s Claude Mythos Preview – challenges this accepted status quo. During their initial evaluation with Claude Mythos Preview, the Firefox team identified and fixed 271 vulnerabilities for their version 150 release. This followed a prior collaboration with Anthropic using Opus 4.6, which yielded 22 security-sensitive fixes in version 148. Uncovering hundreds of vulnerabilities simultaneously puts a heavy strain on a team’s resources.…