Claude Opus 4.6 Resists 6,000 Prompt Injection Attempts
A public challenge exposing an AI email assistant to over 6,000 prompt injection attempts found that Claude Opus 4.6 successfully resisted all efforts to leak secrets or execute malicious instructions embedded in emails. While the result suggests frontier model training against injection attacks is meaningfully improving, security researchers caution that the absence of a successful attack under constrained conditions does not constitute a security guarantee. The author and Hacker News community both note that sophisticated or novel attack vectors could still break through, and irreversible-damage scenarios should not rely solely on model-level defences.