Claude AI finds 500 high-severity software vulnerabilities

Anthropic is reporting the flaws to developers — but only after having humans verify them.

Anthropic only released its latest large language model, Claude Opus 4.6, on Thursday, but it has already been using it behind the scenes to identify zero-day vulnerabilities in open-source software.

In the trial, it put Claude inside a virtual machine with access to the latest versions of open source projects, and provided it with a range of standard utilities and vulnerability analysis tools, but no instructions on how to use them nor how specifically to identify vulnerabilities.

Despite this lack of guidance, Opus 4.6 managed to identify a 500 high-severity vulnerabilities. Anthropic staff are validating the findings before reporting the bugs to their developers to ensure the LLM was not hallucinating or reporting false positives, according to company blog post.