Anthropic reports fourth cybersecurity incident with early version of Claude

Anthropic said on Wednesday it had identified a fourth cybersecurity incident involving an early version of its Claude AI model.

The company said ‌in ⁠a ⁠blog post the incident occurred ​in January and involved an early version of ​Claude Opus 4.6. It has notified all the affected parties but ​did not disclose ⁠more details.

Anthropic had ‌disclosed in July ​some ​of its Claude AI models ⁠had hacked into the systems of ​three companies during cybersecurity tests.


AI companies are under scrutiny over AI breakout events, including cases where AI agents have inadvertently been unleashed on to the ‌open internet.

Over the past week, Reuters reported that ​rogue agents ​from OpenAI ⁠hijacked a German-language wiki and a host of other sites - an incident ​OpenAI chose not to disclose until the news agency made it public.