{"schema_version":"0.10.0","id":"LR-2026-0529","record_version":1,"title":"Mercor data breach via LiteLLM supply-chain compromise (April 2026)","verification":{"human_verified":false,"method":"automated_gate","auto_verified":true,"score":55.4,"score_breakdown":{"source_authority":12.1,"independent_corroboration":15.0,"implicated_party_confirmed":0.0,"citation_integrity":14.0,"specificity":3.0,"completeness":3.52,"unhedged_language":5.0},"checks":{"schema_valid":true,"every_field_cited":true,"quotes_verbatim":true,"source_fetched":true,"distinct_incident":true,"dates_plausible":true,"sources_agree":true,"source_describes_incident":true,"severe_backed_by_source":true,"record_integrity":true,"eligible":true,"about_this_case":true},"gate_version":"gate-2026-10-18.7","cross_check_model":null,"cross_check_agreement":null,"duplicate_of":null,"verified_by":null,"verified_at":"2026-11-01","extraction_run_id":null,"evidence_level":{"level":"preliminary","reason":"Publisher not yet named · subject to change","original_document":null,"reports_total":2,"reports_independent":0,"reports_derivative":0,"developing":false,"disputed":false,"rules_version":"evidence-2026-10-29.1","computed_at":"2026-11-01","history":[{"date":"2026-11-01","from_level":null,"to_level":"preliminary","reason":"Publisher not yet named · subject to change"}]},"sources_hash":"c0376eed1fa76d77c0db7110edba5ae02abeda3c35ecc63aa3e2bccb65aeec78"},"system":{"model_name":null,"model_version":null,"developer":"unknown","harness":null,"tools_granted":[],"permissions_scope":null,"autonomy_level":"unknown","guardrails_present":[],"deployment_context":"unknown","tier":null,"lifecycle_stage":null,"integration_type":null,"intended_use":null,"safeguard_state":null,"production_intended":null},"event":{"date_occurred":"2026-04-01","date_occurred_precision":"month","date_disclosed":"2026-04-23","incident_class":"security_compromise","failure_class":null,"agent_involved":null,"secondary_failure_classes":[],"trigger":"unknown","duration":null,"detection_method":"unknown","summary":"Mercor, a contractor that hires experts to help train AI models, was hit by a security compromise in April 2026. According to Halborn, the attack began with attackers compromising Trivy, a security scanning tool, and then inserting malicious code into LiteLLM, a widely used Python library the company used. Infostealer malware in the LiteLLM code gave the attacker credentials for Mercor systems and environments, and the attacker reportedly stole an estimated 4TB of data including Slack data, ticketing information, videos of contractors, database records and source code. Compromised contractor data includes passport scans, Social Security Numbers and video interviews. The Wall Street Journal reported that at least seven class-action lawsuits were served after the breach, and Meta said it had paused its work with Mercor and was investigating.","tags":[],"date_detected":null,"near_miss":null,"root_cause":null,"root_cause_detail":null,"failure_class_detail":null,"responsible_party":null,"adversarial_actor":null,"input_provenance":null,"time_to_contain":null,"operations_paused":null,"remediation":null,"precursor_events":null,"primary_risk":"RK06","secondary_risks":["RK04"]},"impact":{"direct_loss_usd":null,"remediation_hours":null,"records_exposed":null,"third_parties_affected_count":null,"severity":"major","severity_because":"major test: many third parties affected, as Mercor noted thousands of companies were impacted by the LiteLLM breach","harm_class":[],"affected_description":null,"protected_class_involved":null,"data_categories_exposed":["passport scans","Social Security Numbers","video interviews"],"loss_range_usd":null,"reversibility":null,"downstream_exposure_count":null},"evidence":{"sources":[{"url":"https://www.pymnts.com/legal/2026/ai-startup-mercor-faces-lawsuit-over-data-breach/","publisher":"PYMNTS.com","date":"2026-04-23","type":"press","title":"AI Startup Mercor Faces Lawsuit Over Data Breach - PYMNTS.com","archived_url":null,"attachment":"first_report"},{"url":"https://www.halborn.com/blog/post/explained-the-mercor-hack-april-2026","publisher":"Halborn","date":"2026-04-24","type":"press","title":"Explained: The Mercor Hack (April 2026) - Halborn","archived_url":null}],"per_field_confidence":{"event.incident_class":"C","event.date_occurred":"C","impact.data_categories_exposed":"C","impact.severity":"D","impact.severity_because":"D","event.primary_risk":"D","event.secondary_risks":"D","event.summary":"C","system.autonomy_level":"D","system.deployment_context":"D","event.trigger":"D","event.detection_method":"D","context.country":"D","system.developer":"D","event.date_disclosed":"D","context.denominator_available":"D"},"field_citations":{"event.incident_class":[{"source_index":1,"quote":"In April 2026, Mercor, a company that supports several major LLM developers (Anthropic, Meta, and OpenAI), was the victim of a hack."}],"event.date_occurred":[{"source_index":1,"quote":"In April 2026, Mercor, a company that supports several major LLM developers (Anthropic, Meta, and OpenAI), was the victim of a hack."}],"impact.data_categories_exposed":[{"source_index":1,"quote":"Compromised contractor data includes passport scans, Social Security Numbers (SSNs), and video interviews."}],"impact.severity":[{"source_index":1,"quote":"As Mercor noted, thousands of companies were impacted by the LiteLLM breach, and the others may not have realized that their environments and credentials had been compromised."}],"impact.severity_because":[{"source_index":1,"quote":"As Mercor noted, thousands of companies were impacted by the LiteLLM breach, and the others may not have realized that their environments and credentials had been compromised."}],"event.summary":[{"source_index":1,"quote":"In April 2026, Mercor, a company that supports several major LLM developers (Anthropic, Meta, and OpenAI), was the victim of a hack."},{"source_index":1,"quote":"The hack began with attackers compromising Trivy, a security scanning tool."},{"source_index":1,"quote":"The company uses LiteLLM, and the infostealer malware injected into the LiteLLM code provided the attacker with credentials for Mercor systems and environments."},{"source_index":1,"quote":"From there, the attacker was able to access various internal systems and tools, stealing an estimated 4TB of Slack data, ticketing information, videos of contractors, database records, and source code."},{"source_index":1,"quote":"Compromised contractor data includes passport scans, Social Security Numbers (SSNs), and video interviews."},{"source_index":0,"quote":"The $10 billion company, which has worked with the likes of Meta, has been served with at least seven class-action lawsuits in the wake of the breach, The Wall Street Journal (WSJ) reported Thursday (April 23)."},{"source_index":0,"quote":"The WSJ report added a comment from a Meta spokesperson that the company has paused its work with Mercor and is investigating the breach."}]},"notes_on_gaps":"The sources describe a breach of Mercor (a contractor for AI developers) through a supply-chain compromise of Trivy and the LiteLLM library. No AI agent is described as autonomous or involved, so agent_involved, failure_class and secondary classes are omitted. No AI system under test is identified as the implicated system, so system fields are omitted. Detection method, containment time, disclosure date, duration, record counts, direct loss and remediation steps are not stated. No specific control is reported as held, failed or missing, so links are empty. Mercor's statement that it acted quickly to remedy the breach gives no specifics, so no remediation is recorded. Halborn's 4TB figure is an estimate attributed to the attacker and is presented as estimated. The lawsuit allegations are plaintiffs' claims that Mercor disputes, not findings. The claim about unauthorized use of the Mythos model and the Claude Code leak concern other systems and are excluded. Judgements made: root_cause set to integration and trigger to credential_exposure from the cited sentences; responsible_party set to third_party for the attackers; severity set to major because thousands of companies were stated as impacted, and the severity_because text repeats that fact. The adversarial actor is not stated as external or otherwise, so it is omitted. The 2026-04-23 timeline date is the WSJ report date, not confirmed as the date of the lawsuits. [case created by the backfill: read by claude-haiku-5-5, backfill-2026-11-01.2, 2026-11-01; not yet reviewed] [2026-11-01: evidence level set: Preliminary (Publisher not yet named · subject to change)]"},"context":{"industry":null,"org_size_band":null,"country":"unknown","denominator_available":false,"denominator":null,"related_incident_ids":[],"systemic_exposure":null,"shared_model_id":null,"upstream_incident_id":null,"incident_evidence":null,"regulatory":null,"coverage":null},"narrative":{"steps":[{"step":"reached","text":"The attacker reached internal systems and reportedly took an estimated 4TB of data.","quote":"From there, the attacker was able to access various internal systems and tools, stealing an estimated 4TB of Slack data, ticketing information, videos of contractors, database records, and source code.","source_index":1,"grade":"C"},{"step":"done","text":"At least seven class-action lawsuits were served after the breach.","quote":"The $10 billion company, which has worked with the likes of Meta, has been served with at least seven class-action lawsuits in the wake of the breach, The Wall Street Journal (WSJ) reported Thursday (April 23).","source_index":0,"grade":"C"}],"model":"claude-haiku-5-5","prompt_version":"backfill-2026-11-01.2","extracted_at":"2026-11-01","source_urls":["https://www.pymnts.com/legal/2026/ai-startup-mercor-faces-lawsuit-over-data-breach/","https://www.halborn.com/blog/post/explained-the-mercor-hack-april-2026"]},"analysis":{"sections":{"timeline":[{"text":"Mercor was hacked.","quote":"In April 2026, Mercor, a company that supports several major LLM developers (Anthropic, Meta, and OpenAI), was the victim of a hack.","source_index":1,"when":"2026-04"},{"text":"WSJ reported at least seven class-action lawsuits served after the breach.","quote":"The $10 billion company, which has worked with the likes of Meta, has been served with at least seven class-action lawsuits in the wake of the breach, The Wall Street Journal (WSJ) reported Thursday (April 23).","source_index":0,"when":"2026-04-23"},{"text":"Meta said it had paused its work with Mercor and was investigating.","quote":"The WSJ report added a comment from a Meta spokesperson that the company has paused its work with Mercor and is investigating the breach.","source_index":0,"when":null}]},"model":"claude-haiku-5-5","prompt_version":"backfill-2026-11-01.2","extracted_at":"2026-11-01","source_urls":["https://www.pymnts.com/legal/2026/ai-startup-mercor-faces-lawsuit-over-data-breach/","https://www.halborn.com/blog/post/explained-the-mercor-hack-april-2026"]}}