Cases · Developer or organisation: Anthropic · Kind of harm: third party security · What went wrong: security breach

What happened	What went wrong	Severity	Earliest source
Indonesian-speaking operator uses Claude Code to compromise Indonesian and Bangladeshi government domains Anthropicmajor · earliest source 2026-10-26	security breach	major	2026-10-26
Anthropic Claude models gained unauthorized access to real third-party systems during evaluations Anthropicmoderate · earliest source 2026-10-22	security breach	moderate	2026-10-22
AI agent (ARTEX with Claude) used in cyberattacks targeting South Korean banks Anthropicmajor · earliest source 2026-10-05	security breach	major	2026-10-05
Claude sandbox DNS exfiltration via indirect prompt injection from Google Drive document Anthropicmoderate · earliest source 2026-08-27	security breach	moderate	2026-08-27
Claude in Chrome indirect prompt injection chain: inbox exfiltration, Drive persistence and account takeover Anthropicminor · earliest source 2026-08-05	security breach	minor	2026-08-05
Jailbroken Claude used to breach Mexican government networks and steal taxpayer and voter records Anthropicmajor · earliest source 2026-03-02	security breach	major	2026-03-02