Anthropic says Opus 4.6 found 500+ previously unknown high-severity security flaws in open-source libraries with little to no prompting during its testing (Sam Sabin/Axios)

Anthropic's Opus 4.6 found over 500 previously unknown high-severity security flaws in open-source libraries. The discovery was made with little to no prompting during testing. Opus 4.6 was tested in a sandboxed environment by Anthropic's frontier red team.