{
 "public_id": "AIR-2026-0206",
 "incident_id": "2026-08-tooluniverse-sandbox-escape-unauth-rce",
 "date_disclosed": "2026-08-27",
 "date_occurred": null,
 "title": "CVE-2026-81096: ToolUniverse Python sandbox escape plus unauthenticated MCP/HTTP servers bound to all interfaces",
 "class": "responsible_disclosure",
 "attack_surface": "mcp_server",
 "initial_vector": "caller_supplied_python_to_an_unauthenticated_endpoint",
 "agent_capability_abused": [
  "python_code_execution",
  "tool_server_exposure"
 ],
 "target_product": "ToolUniverse",
 "target_vendor": "ToolUniverse maintainers",
 "autonomy_level": "semi_autonomous",
 "impact_realized": false,
 "impact_type": [
  "sandbox_escape",
  "remote_code_execution"
 ],
 "blast_radius": "ToolUniverse through 1.2.6, exposed on every interface with debugging on and no auth",
 "cve": [
  "CVE-2026-81096"
 ],
 "taxonomy": {
  "owasp_asi": [
   "ASI05"
  ],
  "mitre_atlas": [],
  "labels": [
   "sandbox_escape",
   "subclass_walk",
   "missing_authentication",
   "bind_all_interfaces",
   "tool_server"
  ]
 },
 "defense_present": "a Python code-execution sandbox that still exposed attribute-lookup builtins",
 "defense_bypassed": true,
 "fix_shipped": "ToolUniverse 1.3.0 - bearer-token auth, loopback-only bind, stricter attribute validation",
 "primary_sources": [
  "https://github.com/advisories/GHSA-rg68-wg77-c3wm"
 ],
 "verified_quote": "walk from a literal's class to its base and enumerate subclasses to obtain a reference to the process and subprocess modules.",
 "confidence": "high",
 "notes": "GHSA-rg68-wg77-c3wm, CVSS 9.3 Critical, published 2026-08-27. The classic Python subclass-walk sandbox escape, still shipping inside agent tool servers in 2026. Included as a representative of the 'MCP tool server with no auth plus a homemade Python sandbox' pattern seen repeatedly in the August 2026 batch of unreviewed MCP advisories.",
 "risk_category": "security_fraud",
 "risk_secondary": [],
 "risk_subcategory": "Remote Code Execution & Sandbox Escape",
 "risk_sub_secondary": [
  "Over-permissioned execution & lateral movement"
 ],
 "ai_entity": "generative",
 "agency": "ai_as_target",
 "agency_debatable": false,
 "agency_reason": "a Python sandbox escape on unauthenticated MCP/HTTP servers",
 "vector_family": "conventional_vulnerability",
 "vector_detail": "caller_supplied_python_to_an_unauthenticated_endpoint",
 "guardrail_kind": [
  "sandbox_isolation"
 ],
 "guardrail_outcome": "silent",
 "xrefs": {
  "aiid": [],
  "atlas": [],
  "cve": [
   "CVE-2026-81096"
  ],
  "ghsa": []
 },
 "primary_asi": "ASI05",
 "agent_framework": "mcp_server",
 "model_provider": "unknown",
 "model_name": "",
 "detection_mechanism": "unknown",
 "tool_access": "unknown",
 "financial_loss_band": "unknown",
 "eai_category": "privilege_escalation",
 "eai_domain": "access_control_and_permissions",
 "eai_secondary": [],
 "eai_reason": "subcategory: Remote Code Execution & Sandbox Escape",
 "asi_curated": [],
 "asi_scope": "in_scope",
 "asi_provenance": "rule",
 "asi_reason": "ASI05 (impact=code_exec)",
 "submitted_by": "EAI Internal"
}