{
 "public_id": "AIR-2026-0031",
 "incident_id": "2026-02-n8n-expression-sandbox-escape",
 "date_disclosed": "2026-02-04",
 "date_occurred": null,
 "title": "n8n expression sandbox escape: template literals, arrow functions and Object.defineProperty defeat the AST sanitizer for full server takeover (CVE-2026-25049)",
 "class": "responsible_disclosure",
 "attack_surface": "agent_framework",
 "initial_vector": "authenticated_workflow_expression_injection",
 "agent_capability_abused": [
  "workflow_expression_evaluation",
  "credential_store_access"
 ],
 "target_product": "n8n (self-hosted and Cloud)",
 "target_vendor": "n8n",
 "autonomy_level": "semi_autonomous",
 "impact_realized": false,
 "impact_type": [
  "remote_code_execution",
  "credential_theft",
  "cross_tenant_exposure"
 ],
 "blast_radius": "self-hosted and n8n Cloud instances; every credential stored in the instance",
 "cve": [
  "CVE-2026-25049"
 ],
 "taxonomy": {
  "owasp_asi": [
   "ASI04",
   "ASI05",
   "ASI03"
  ],
  "mitre_atlas": [],
  "labels": [
   "sandbox_escape",
   "ast_sanitizer_bypass",
   "credential_vault_compromise",
   "incomplete_patch"
  ]
 },
 "defense_present": "AST-based expression sandbox restricting property access",
 "defense_bypassed": true,
 "fix_shipped": "n8n 2.4.0 (January 2026); first patch 2025-12-23 was incomplete and bypassed 2025-12-24",
 "primary_sources": [
  "https://www.pillar.security/blog/n8n-sandbox-escape-critical-vulnerabilities-in-n8n-exposes-hundreds-of-thousands-of-enterprise-ai-systems-to-complete-takeover"
 ],
 "verified_quote": "The access we gained allowed us to execute arbitrary system commands on the n8n server [and] decrypt every stored credential in the database.",
 "confidence": "high",
 "notes": "Pillar Security (Eilon Cohen). Discovered 2025-12-21; incomplete patch 2025-12-23; Object.defineProperty bypass 2025-12-24; full fix in 2.4.0; coordinated disclosure 2026-02-04. CVSS 10.0. Extracting N8N_ENCRYPTION_KEY turns one workflow author into full credential-vault compromise. Distinct from CVE-2025-68613 (2025-12-n8n-expression-injection-rce) and the Rapid7 Ni8mare/N8scape pair (2026-01-n8n-ni8mare-n8scape-cluster).",
 "risk_category": "security_fraud",
 "risk_secondary": [],
 "risk_subcategory": "Credential & Secret Theft",
 "risk_sub_secondary": [
  "Remote Code Execution & Sandbox Escape"
 ],
 "ai_entity": "generative",
 "agency": "ai_as_target",
 "agency_debatable": false,
 "agency_reason": "an AST sanitizer bypass gives full server takeover",
 "vector_family": "other",
 "vector_detail": "authenticated_workflow_expression_injection",
 "guardrail_kind": [
  "sandbox_isolation"
 ],
 "guardrail_outcome": "silent",
 "xrefs": {
  "aiid": [],
  "atlas": [],
  "cve": [
   "CVE-2026-25049"
  ],
  "ghsa": []
 },
 "primary_asi": "ASI04",
 "agent_framework": "n8n",
 "model_provider": "unknown",
 "model_name": "",
 "detection_mechanism": "external_researcher",
 "tool_access": "unknown",
 "financial_loss_band": "unknown",
 "eai_category": "credential_theft",
 "eai_domain": "access_control_and_permissions",
 "eai_secondary": [
  "privilege_escalation"
 ],
 "eai_reason": "subcategory: Credential & Secret Theft",
 "asi_curated": [
  "ASI04"
 ],
 "asi_scope": "in_scope",
 "asi_provenance": "curated_plus_rule",
 "asi_reason": "curated: ASI04 | added ASI05 (impact=code_exec), ASI03 (eai_category=credential_theft)",
 "submitted_by": "EAI Internal"
}