According to Mozilla’s blog post, the Firefox team applied an early version of Anthropic’s unreleased Claude Mythos Preview to scan the browser and shipped fixes for 423 security bugs in April releases, including 271 issues the company attributes to Mythos. Mozilla published a companion post on Hacks.mozilla.org that samples 12 of the bugs and describes one as a 15-year-old defect that had evaded fuzzers. TechCrunch and Ars Technica report Mozilla engineers found the results had “almost no false positives” after combining the model with custom orchestration and filtering. Reporting also highlights concerns about dual-use risk and the scale of latent bugs uncovered. Editorial analysis: For defenders, Mozilla’s findings suggest AI-assisted scanning is rapidly maturing, but it also raises coordination and disclosure tradeoffs across the software ecosystem.
