{
 "public_id": "AIR-2026-0204",
 "incident_id": "2026-08-anthropic-claude-code-opus5-automode",
 "date_disclosed": "2026-08-26",
 "date_occurred": null,
 "title": "Breaking Claude Code Opus 5 Auto Mode: prompt injection plus Python module shadowing to RCE",
 "class": "research_demo",
 "attack_surface": "coding_agent",
 "initial_vector": "indirect_prompt_injection_repo_content",
 "agent_capability_abused": [
  "code_execution",
  "dependency_resolution",
  "network_egress",
  "web_browsing",
  "file_write"
 ],
 "target_product": "Claude Code (Opus 5, Auto Mode)",
 "target_vendor": "Anthropic",
 "autonomy_level": "semi_autonomous",
 "impact_realized": false,
 "impact_type": [
  "code_execution",
  "remote_control",
  "malware_execution",
  "remote_code_execution",
  "c2_control"
 ],
 "blast_radius": "Claude Code users running Auto Mode on untrusted repositories",
 "cve": [],
 "taxonomy": {
  "owasp_asi": [
   "ASI01",
   "ASI05"
  ],
  "mitre_atlas": [],
  "labels": [
   "approval_bypass",
   "module_shadowing",
   "c2",
   "benchmark_gap",
   "indirect_prompt_injection",
   "safety_classifier_bypass"
  ]
 },
 "defense_present": "Auto Mode best-effort classifier (vendor-reported 0.00% ASR on a 72-scenario benchmark)",
 "defense_bypassed": true,
 "fix_shipped": "none; Anthropic classified the report as Informative and scoped injection chains out of the classifier",
 "primary_sources": [
  "https://embracethered.com/blog/posts/2026/breaking-claude-code-opus-5-and-automode/"
 ],
 "verified_quote": "Auto Mode is a convenience feature backed by a best-effort classifier, not a security guarantee.",
 "confidence": "high",
 "notes": "Johann Rehberger, 26 Aug 2026. Python module shadowing combined with indirect prompt injection yields arbitrary code execution at a reported 60-80% success rate, including C2 callback and malware execution. Directly relevant to benchmark-validity work in init.md: Anthropic had published a 0.00% attack success rate for Opus 5 Auto Mode over a fixed 72-scenario benchmark, and this novel chain works outside it - a concrete instance of a static agent benchmark overstating robustness. Also reported as: 'Breaking Claude Code Opus 5 Auto Mode: prompt-injection chain to code execution despite the safety classifier'.",
 "risk_category": "security_fraud",
 "risk_secondary": [],
 "risk_subcategory": "Prompt Injection",
 "risk_sub_secondary": [
  "Remote Code Execution & Sandbox Escape",
  "Persistence & Covert C2"
 ],
 "ai_entity": "generative",
 "agency": "agent_acted",
 "agency_debatable": false,
 "agency_reason": "Claude Code executed the shadowed module and established C2",
 "vector_family": "indirect_prompt_injection",
 "vector_detail": "indirect_prompt_injection_repo_content",
 "guardrail_kind": [
  "input_classifier"
 ],
 "guardrail_outcome": "silent",
 "xrefs": {
  "aiid": [],
  "atlas": [],
  "cve": [],
  "ghsa": []
 },
 "primary_asi": "ASI01",
 "agent_framework": "claude_code",
 "model_provider": "anthropic",
 "model_name": "",
 "detection_mechanism": "external_researcher",
 "tool_access": "unknown",
 "financial_loss_band": "unknown",
 "eai_category": "privilege_escalation",
 "eai_domain": "access_control_and_permissions",
 "eai_secondary": [
  "policy_drift",
  "confused_deputy"
 ],
 "eai_reason": "impact rule: privilege_escalation",
 "asi_curated": [
  "ASI01"
 ],
 "asi_scope": "in_scope",
 "asi_provenance": "curated_plus_rule",
 "asi_reason": "curated: ASI01 | added ASI05 (impact=code_exec)",
 "submitted_by": "EAI Internal"
}