{ "number": 36343, "input_hash": "63cd2c4cf81f123e", "model": "ledger", "prompt_hash": null, "created": "2026-10-31T01:17:08+00:00", "result": { "summary": "Check PSBTInputSignedAndVerified for each input in FinalizePSBT before marking it complete. This prevents FinalizePSBT from unconditionally trusting pre-existing final scriptSig or scriptWitness fields without verifying them against standard execution flags.", "problem": "When a PSBT input has a non-witness UTXO and already contains final script fields, SignPSBTInput accepts them and ProduceSignature returns early before script verification. As a result, finalizepsbt can report complete: true and return a raw transaction hex whose script fails mempool verification, contradicting analyzepsbt which reports the input as not final.", "card": "FinalizePSBT now verifies final scriptSig and scriptWitness data using PSBTInputSignedAndVerified before marking an input complete. Previously, inputs with a non_witness_utxo and existing final fields were trusted without script checks, causing finalizepsbt to return complete: true along with raw transaction hex that fails mempool verification. This aligns FinalizePSBT with fixes previously made to FillPSBT (#30357) and descriptorprocesspsbt (#33014). An intentional side effect is that inputs with consensus-valid but non-standard final scripts will now return complete: false.", "evidence": [ "PR description demonstrates reproduction: flipping a bit in the final witness of a P2WPKH PSBT causes finalizepsbt to output complete: true with a hex that testmempoolaccept rejects with 'mempool-script-verify-flag-failed (Signature must be zero for failed CHECK(MULTI)SIG operation)', while analyzepsbt marks the input not final", "Author cites prior merged fixes applying the same check to other PSBT entry points: #30357 for FillPSBT and #33014 for descriptorprocesspsbt" ], "scope_notes": "Small logic change in FinalizePSBT with an added functional test and release note.", "changed_since_previous": "Added release notes document doc/release-notes-36343.md.", "thread": { "last_event_at": "2026-10-30T11:41:08Z", "events": 5, "head_sha": "7148c65121cbe7225acc9ab789146c3632f9de97", "schema_floor": 2, "schema": 2 }, "waiting_on": [ { "at": "2026-10-30", "id": "c:6521767967", "on": "author", "url": "https://github.com/bitcoin/bitcoin/pull/36343#issuecomment-6521767967", "what": "response to Bicaru20's suggestion on analyzepsbt next role" } ], "risk": { "level": "medium", "touches": [ "rpc_api" ], "why": "A flaw in final script verification could mistakenly reject valid PSBTs or block transaction finalization in RPC workflows." }, "discussion": { "author_status": "last statement processed 2026-10-30", "open_concerns": [ "Bicaru20: Update AnalyzePSBT or SignPSBTInput so that analyzepsbt returns next: updater instead of finalizer when final scriptSig or scriptWitness fields fail verification" ], "resolved_concerns": [ "fametrano: Add a release note describing the behavior change where consensus-valid but non-standard scripts now return complete=false. (accepted by fametrano 2026-10-03)" ] }, "reviewability": { "state": "Ready", "label": "Ready", "reason": "Nothing known that would invalidate a review now." }, "agreement": { "state": "Strong", "summary": "Strong: substantive support, no open objection (fametrano, fametrano)", "reason": "Added Bicaru20's Concept ACK and suggestion regarding updating analyzepsbt to report updater when verification of final scripts fails.", "evidence": [ "Bicaru20 (suggestion, interface, must be answered, open): Update AnalyzePSBT or SignPSBTInput so that analyzepsbt returns next: updater instead of finalizer when final scriptSig or scriptWitness fields fail verification", "fametrano: Tested ACK \u2014 verified the bugfix on pkh, sh-wpkh, wpkh, and taproot inputs; verified non-standard inputs match walletprocesspsbt behavior", "fametrano: ACK \u2014 Only the release note is new since my Tested ACK, and it matches the code.", "l0rinc: Concept ACK", "Bicaru20: Concept ACK" ], "objections": [ { "reviewer": "fametrano", "association": "NONE", "type": "suggestion", "kind": "maintenance", "harm": "", "request": "Add a release note describing the behavior change where consensus-valid but non-standard scripts now return complete=false.", "question": "", "text": "Add a release note describing the behavior change where consensus-valid but non-standard scripts now return complete=false.", "clears_with": "answer", "blocking": false, "status": "accepted", "status_note": "reviewer confirmed the added release note matches the code", "cleared": true, "author_replied": true, "others_replied": false, "fix_pushed": true, "replies": [ "c:5955738380" ], "evidence": "2026-10-02: 'it may deserve a release note'", "url": "https://github.com/bitcoin/bitcoin/pull/36343#issuecomment-5951768922", "id": "c:5951768922", "at": "2026-10-02", "status_at": "2026-10-03", "status_by": "fametrano", "resolution_evidence": "2026-10-03: fametrano: 'Only the release note is new since my Tested ACK, and it matches the code.'", "pin": null, "from_schema": 2 }, { "reviewer": "Bicaru20", "association": "CONTRIBUTOR", "type": "suggestion", "kind": "interface", "harm": "", "request": "Update AnalyzePSBT or SignPSBTInput so that analyzepsbt returns next: updater instead of finalizer when final scriptSig or scriptWitness fields fail verification", "question": "", "text": "Update AnalyzePSBT or SignPSBTInput so that analyzepsbt returns next: updater instead of finalizer when final scriptSig or scriptWitness fields fail verification", "clears_with": "answer", "blocking": false, "status": "open", "status_note": "", "cleared": false, "author_replied": false, "others_replied": false, "fix_pushed": false, "replies": [], "evidence": "2026-10-30: 'Since the final script_sig or final script_witness failed verification and in the same test we see that when trying to finalize the psbt it fails, I belvie this field on `analyzepsbt` can be missleading and should return `updater`.'", "url": "https://github.com/bitcoin/bitcoin/pull/36343#issuecomment-6521767967", "id": "c:6521767967", "at": "2026-10-30", "status_at": null, "status_by": null, "resolution_evidence": "", "pin": null, "from_schema": 2 } ], "support": [ { "reviewer": "fametrano", "reason": "verified the bugfix on pkh, sh-wpkh, wpkh, and taproot inputs; verified non-standard inputs match walletprocesspsbt behavior", "substantive": true, "verdict": "Tested ACK", "id": "c:5951768922", "url": "https://github.com/bitcoin/bitcoin/pull/36343#issuecomment-5951768922", "at": "2026-10-02", "association": "NONE", "evidence": "both", "areas": [] }, { "reviewer": "fametrano", "reason": "Only the release note is new since my Tested ACK, and it matches the code.", "substantive": true, "verdict": "ACK", "id": "c:5968528317", "url": "https://github.com/bitcoin/bitcoin/pull/36343#issuecomment-5968528317", "at": "2026-10-03", "association": "NONE", "evidence": "read", "areas": [ "doc/release-notes.md" ] }, { "reviewer": "l0rinc", "reason": "", "substantive": false, "verdict": "Concept ACK", "id": "c:6468028476", "url": "https://github.com/bitcoin/bitcoin/pull/36343#issuecomment-6468028476", "at": "2026-10-28", "association": "MEMBER", "evidence": "none", "areas": [] }, { "reviewer": "Bicaru20", "reason": "", "substantive": false, "verdict": "Concept ACK", "id": "c:6521767967", "url": "https://github.com/bitcoin/bitcoin/pull/36343#issuecomment-6521767967", "at": "2026-10-30", "association": "CONTRIBUTOR", "evidence": "read", "areas": [ "src/node/psbt.cpp", "test/functional/rpc_psbt.py" ] } ], "participants": [ { "login": "fametrano", "stance": "support", "note": "Tested ACK across multiple input types; reACKed after confirming release note was added", "association": "NONE", "comments": 2, "first": "2026-10-02", "last": "2026-10-03" }, { "login": "l0rinc", "stance": "support", "note": "Concept ACK", "association": "MEMBER", "comments": 1, "first": "2026-10-28", "last": "2026-10-28" }, { "login": "Bicaru20", "stance": "support", "note": "Concept ACK; suggested updating analyzepsbt or SignPSBTInput so next returns updater instead of finalizer when final fields fail verification", "association": "CONTRIBUTOR", "comments": 1, "first": "2026-10-30", "last": "2026-10-30" } ], "derivation": "substantive support, no open objection (fametrano, fametrano)", "model_state": null, "corrections": [], "notes": "Added Bicaru20's Concept ACK and suggestion regarding updating analyzepsbt to report updater when verification of final scripts fails." }, "dependencies": { "depends_on": [], "enables": [] }, "categories": [ { "name": "docs", "member": false, "evidence": "The documentation change is solely an accompanying release note for the PSBT bug fix.", "band": "Unranked", "reason_tag": "bug fix", "score": 0.0, "factors": { "bug_severity": 1, "leverage": 0, "performance": 0, "security_stability": 1, "user_value": 1 }, "rationale": "A code change that updates its release notes is excluded from the documentation category." }, { "name": "rpc", "member": true, "evidence": "Modifies FinalizePSBT behavior exposed by the finalizepsbt RPC without wallet code, which the wallet category explicitly routes to rpc.", "band": "P3", "reason_tag": "bug fix", "score": 0.4, "factors": { "bug_severity": 1, "leverage": 0, "performance": 0, "security_stability": 1, "user_value": 1 }, "rationale": "Prevents finalizepsbt from falsely returning 'complete: true' and emitting an invalid raw transaction hex when pre-existing final scripts fail verification. As the reproduction notes, an invalid witness could previously cause finalizepsbt to claim completion while testmempoolaccept rejected the transaction with a script verification failure." }, { "name": "wallet", "member": false, "evidence": "Touches only src/psbt.cpp and RPC tests without altering wallet-specific code or data structures.", "band": "Unranked", "reason_tag": "bug fix", "score": 0.0, "factors": { "bug_severity": 1, "leverage": 0, "performance": 0, "security_stability": 1, "user_value": 1 }, "rationale": "Under the category definition, PSBT changes that affect RPC without modifying wallet code belong to rpc rather than wallet." } ], "confidence": "high", "uncertainties": [], "needs": [] }, "cost_usd": 0.0, "source": { "record": "2026-10-31T01:17:08+00:00", "code": "2026-10-04T01:20:29+00:00", "judgments": 3 } }