{
 "public_id": "AIR-2026-0100",
 "incident_id": "2026-05-microsoft-copirate-365",
 "date_disclosed": "2026-05-04",
 "date_occurred": null,
 "title": "Copirate 365 at DEF CON: data exfiltration, memory hijacking and a persistent backdoor in Microsoft Copilot (CVE-2026-24299)",
 "class": "research_demo",
 "attack_surface": "enterprise_assistant",
 "initial_vector": "indirect_prompt_injection_content",
 "agent_capability_abused": [
  "html_preview_rendering",
  "delayed_tool_invocation",
  "long_term_memory_write",
  "retrieval",
  "memory_write"
 ],
 "target_product": "Microsoft 365 Copilot; Consumer Copilot",
 "target_vendor": "Microsoft",
 "autonomy_level": "assistant",
 "impact_realized": false,
 "impact_type": [
  "data_exfiltration",
  "memory_poisoning",
  "persistence",
  "persistent_memory_poisoning"
 ],
 "blast_radius": "M365 Copilot and consumer Copilot users",
 "cve": [
  "CVE-2026-24299"
 ],
 "taxonomy": {
  "owasp_asi": [
   "ASI01",
   "ASI06",
   "ASI02"
  ],
  "mitre_atlas": [],
  "labels": [
   "conference_demo",
   "delayed_tool_invocation",
   "memory_poisoning",
   "persistent_backdoor",
   "indirect_prompt_injection",
   "css_font_exfiltration",
   "zero_click"
  ]
 },
 "defense_present": "Microsoft Copilot injection classifiers and link/render restrictions",
 "defense_bypassed": true,
 "fix_shipped": "CVE-2026-24299 assigned; Microsoft fix associated with the CVE",
 "primary_sources": [
  "https://embracethered.com/blog/posts/2026/defcon-talk-copirate-365/"
 ],
 "verified_quote": "data exfiltration via the HTML preview feature, Delayed Tool Invocation as an exploit reliability trick, hijacking long-term memory, and combining all of the above into a persistent backdoor",
 "confidence": "high",
 "notes": "Johann Rehberger, talk given at DEF CON Singapore 2026; blog post 4 May 2026. The chained result - exfiltration plus memory hijack equals a persistent backdoor in a shipped enterprise assistant - is the significant part. Successor to the 2024 'Living off Microsoft Copilot' line of work by Michael Bargury (see quarantine). Also reported as: 'Copirate 365: HTML-preview and memory-based data exfiltration from Microsoft Copilot (CVE-2026-24299)'.",
 "risk_category": "security_fraud",
 "risk_secondary": [
  "privacy"
 ],
 "risk_subcategory": "Prompt Injection",
 "risk_sub_secondary": [
  "Supply Chain Compromise",
  "Persistence & Covert C2"
 ],
 "ai_entity": "generative",
 "agency": "agent_acted",
 "agency_debatable": false,
 "agency_reason": "Copilot rendered, wrote memory and persisted the backdoor",
 "vector_family": "indirect_prompt_injection",
 "vector_detail": "indirect_prompt_injection_content",
 "guardrail_kind": [
  "input_classifier"
 ],
 "guardrail_outcome": "silent",
 "xrefs": {
  "aiid": [],
  "atlas": [],
  "cve": [
   "CVE-2026-24299"
  ],
  "ghsa": []
 },
 "primary_asi": "ASI01",
 "agent_framework": "m365_copilot",
 "model_provider": "microsoft",
 "model_name": "",
 "detection_mechanism": "external_researcher",
 "tool_access": "unknown",
 "financial_loss_band": "unknown",
 "eai_category": "data_and_memory_poisoning",
 "eai_domain": "reliability_and_observability",
 "eai_secondary": [
  "privilege_escalation",
  "data_exfiltration_channels",
  "confused_deputy"
 ],
 "eai_reason": "impact rule: data_and_memory_poisoning",
 "asi_curated": [
  "ASI01"
 ],
 "asi_scope": "in_scope",
 "asi_provenance": "curated_plus_rule",
 "asi_reason": "curated: ASI01 | added ASI06 (eai_category=data_and_memory_poisoning), ASI02 (impact=tool_misuse)",
 "submitted_by": "EAI Internal"
}