{"schema_version":"0.10.0","id":"LR-2026-0423","record_version":1,"title":"Moonwell DeFi lending protocol exploit via AI co-authored oracle misconfiguration","verification":{"human_verified":false,"method":"automated_gate","auto_verified":true,"score":55.1,"score_breakdown":{"source_authority":12.1,"independent_corroboration":15.0,"implicated_party_confirmed":0.0,"citation_integrity":14.0,"specificity":3.0,"completeness":3.2,"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":"1 report: ForkLog · subject to change","original_document":null,"reports_total":2,"reports_independent":1,"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":"1 report: ForkLog · subject to change"}]},"sources_hash":"ee78437d604a88dd5a5998738ace8822046233cfb7db0dcecc59098099d85d74"},"system":{"model_name":null,"model_version":null,"developer":"Anthropic","harness":null,"tools_granted":[],"permissions_scope":null,"autonomy_level":"unknown","guardrails_present":[],"deployment_context":"production","tier":null,"lifecycle_stage":"production","integration_type":null,"intended_use":null,"safeguard_state":null,"production_intended":null},"event":{"date_occurred":null,"date_disclosed":"2026-02-18","incident_class":"operational_error","failure_class":null,"agent_involved":null,"secondary_failure_classes":[],"trigger":"unknown","duration":null,"detection_method":"unknown","summary":"Moonwell, a DeFi lending protocol on Base and Optimism, used smart contracts whose pull requests included commits co-authored by Anthropic's Claude Opus 4.6. A governance proposal misconfigured the cbETH oracle by using the cbETH/ETH exchange rate alone, so the system reported cbETH at about $1.12 instead of about $2,200. Liquidation bots and opportunistic borrowers exploited the mispricing, and the protocol reported about $1.78 million lost. Moonwell's risk manager reduced the cbETH borrowing limit to 0.01 once the problem was discovered. Security auditor Pashov linked the case to vibe coding but said blaming the AI alone is incorrect. Existing audits and tests failed to catch the bug.","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},"impact":{"direct_loss_usd":null,"remediation_hours":null,"records_exposed":null,"third_parties_affected_count":null,"severity":"moderate","severity_because":"Moderate by judgement: user funds of others were touched (financial loss to borrowers and the protocol), with scope bounded to Moonwell's cbETH markets on Base and Optimism; no count of affected parties is stated.","harm_class":[],"affected_description":null,"protected_class_involved":null,"data_categories_exposed":[],"loss_range_usd":null,"reversibility":null,"downstream_exposure_count":null},"evidence":{"sources":[{"url":"https://forklog.com/en/vibe-coding-via-claude-opus-leads-to-moonwell-defi-project-breach/","publisher":"ForkLog","date":"2026-02-18","type":"press","title":"Vibe Coding via Claude Opus Leads to Moonwell DeFi Project Breach - ForkLog","archived_url":null,"attachment":"first_report","independence":"independent"},{"url":"https://www.tradingview.com/news/cointelegraph:17d2ac684094b:0-moonwell-hit-by-1-78m-exploit-as-ai-vibe-coding-debate-reaches-defi/","publisher":"TradingView","date":"2026-02-18","type":"press","title":"Moonwell hit by $1.78M exploit as AI vibe coding debate reaches DeFi - TradingView","archived_url":null}],"per_field_confidence":{"system.developer":"C","system.deployment_context":"C","system.lifecycle_stage":"C","context.industry":"C","event.incident_class":"D","impact.severity":"D","impact.severity_because":"D","event.summary":"C","system.autonomy_level":"D","event.trigger":"D","event.detection_method":"D","context.country":"D","event.date_disclosed":"D","context.denominator_available":"D"},"field_citations":{"system.developer":[{"source_index":1,"quote":"The pull requests for the affected contracts show multiple commits co-authored by Anthropic’s Claude Opus 4.6, prompting security auditor Pashov to publicly flag the incident as an example of artificial intelligence-written or AI-assisted Solidity backfiring."}],"system.deployment_context":[{"source_index":1,"quote":"Moonwell, a decentralized finance (DeFi) lending protocol deployed on Base and Optimism, was exploited for about $1.78 million after a pricing oracle for Coinbase Wrapped Staked ETH (cbETH) returned a value of about $1.12 instead of $2,200, creating a mispricing that attackers were able to use for profit."}],"system.lifecycle_stage":[{"source_index":1,"quote":"Moonwell, a decentralized finance (DeFi) lending protocol deployed on Base and Optimism, was exploited for about $1.78 million after a pricing oracle for Coinbase Wrapped Staked ETH (cbETH) returned a value of about $1.12 instead of $2,200, creating a mispricing that attackers were able to use for profit."}],"context.industry":[{"source_index":1,"quote":"Moonwell, a decentralized finance (DeFi) lending protocol deployed on Base and Optimism, was exploited for about $1.78 million after a pricing oracle for Coinbase Wrapped Staked ETH (cbETH) returned a value of about $1.12 instead of $2,200, creating a mispricing that attackers were able to use for profit."}],"event.incident_class":[{"source_index":1,"quote":"Moonwell said in an incident post-mortem that a governance proposal executed on Sunday misconfigured the cbETH oracle by using the cbETH/ETH exchange rate alone, causing the system to report cbETH at about $1.12."}],"impact.severity":[{"source_index":1,"quote":"Moonwell, a decentralized finance (DeFi) lending protocol deployed on Base and Optimism, was exploited for about $1.78 million after a pricing oracle for Coinbase Wrapped Staked ETH (cbETH) returned a value of about $1.12 instead of $2,200, creating a mispricing that attackers were able to use for profit."}],"impact.severity_because":[{"source_index":1,"quote":"Moonwell, a decentralized finance (DeFi) lending protocol deployed on Base and Optimism, was exploited for about $1.78 million after a pricing oracle for Coinbase Wrapped Staked ETH (cbETH) returned a value of about $1.12 instead of $2,200, creating a mispricing that attackers were able to use for profit."}],"event.summary":[{"source_index":1,"quote":"Moonwell, a decentralized finance (DeFi) lending protocol deployed on Base and Optimism, was exploited for about $1.78 million after a pricing oracle for Coinbase Wrapped Staked ETH (cbETH) returned a value of about $1.12 instead of $2,200, creating a mispricing that attackers were able to use for profit."},{"source_index":1,"quote":"The pull requests for the affected contracts show multiple commits co-authored by Anthropic’s Claude Opus 4.6, prompting security auditor Pashov to publicly flag the incident as an example of artificial intelligence-written or AI-assisted Solidity backfiring."},{"source_index":1,"quote":"Moonwell said in an incident post-mortem that a governance proposal executed on Sunday misconfigured the cbETH oracle by using the cbETH/ETH exchange rate alone, causing the system to report cbETH at about $1.12."},{"source_index":0,"quote":"As soon as the problem was discovered, our risk manager @anthiasxyz promptly reduced the cbETH borrowing limit to 0.01 to limit further risks to the protocol,” Moonwell representatives wrote."},{"source_index":1,"quote":"Pashov cautioned, however, against treating the flaw as uniquely AI-driven."},{"source_index":1,"quote":"What makes Moonwell notable is the mix of AI co-authorship, a basic-seeming price configuration failure on a major asset, and existing audits and tests that failed to catch it."}]},"notes_on_gaps":"Sources do not state the Moonwell post-mortem date, the detection method, or the date of disclosure; source dates are publication dates only and were not used as event dates. Sources do not state the exact loss beyond 'about $1.78 million', nor any count of affected parties, so severity is a judgement (moderate, bounded scope) and no third_parties count is given. Claude Opus 4.6 is described only as co-authoring commits; no autonomous agent action is stated, so agent_involved is set false and no failure_class is given. Root cause 'oversight' is a judgement drawn from Pashov's view; responsible_party is not assigned. Pashov first said there was no testing or audit, later acknowledged unit and integration tests and a Halborn audit; the outcome for I1 is inferred from the press statement that existing audits and tests failed to catch the bug. The control A7 for the borrowing-limit reduction is a judgement that a borrow cap is a rate or spend limit. RK14 is a judgement: the false oracle price was acted on by liquidation bots. Trigger, adversarial intent beyond trading bots, and any post-mortem details beyond press reports are not stated. [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 (1 report: ForkLog · subject to change)]"},"context":{"industry":"decentralized finance (lending protocol)","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}}