Anthropic says it found a heap of Firefox security flaws using new Claude tools, says 'AI is making it possible to detect severe security vulnerabilities at highly accelerated speeds'

• Anthropic Claude Opus 4.6 uncovers 22 Firefox security flaws
• Mozilla confirmed 14 high-severity vulnerabilities patched in Firefox 148
• AI model demonstrated accelerated, human-like vulnerability detection

Anthropic says it found almost two dozen vulnerabilities in the latest version of Mozilla’s Firefox browser, including a few that could have caused serious damage.

In a new blog post Anthropic said it teamed up with Mozilla’s researchers and, over the course of a couple weeks, scanned almost 6,000 C++ files using Claude Opus 4.6.

Opus 4.6 is the latest version of Anthropic’s most powerful large language model (LLM), which was released in early February 2026, and has been advertised as a must-have tool in every cyber defender’s arsenal, claiming it is “notably better” at finding high-severity vulnerabilities.

Article continues below