After OpenAI, Anthropic finds Claude breached three organizations during cyber tests

During cybersecurity testing, Anthropic's Claude AI models gained unauthorized access to real company systems on three separate occasions in April because the evaluation environment was misconfigured and had internet access when it should have been isolated. The most serious incident involved Claude Opus 4.7 exploiting vulnerabilities in a real company's infrastructure to access a production database, while another incident saw Claude Mythos 5 publish a malicious Python package (pre-written code) to a public repository that was downloaded by 15 real systems before removal.