An early version of Claude Opus 4.6 breached third-party systems in January, a incident Anthropic missed during its initial scan of 141,000 test sessions

Anthropic discloses a fourth security incident involving Claude Opus 4.6, including a January 2026 breach that exposed 150 GB of Mexican

Sept 9 : Anthropic on Wednesday identified a fourth cybersecurity incident involving an early version of its Claude AI model, a month after disclosing that the chatbot had hacked…