{"items":[{"id":"NVI-00017562","kind":"vulnerability","title":"Zebra: Missing copy constraint in halo2_gadgets variable-base scalar multiplication allows under-constrained base, breaking Orchard Action circuit soundness","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-ww9q-8r59-xv46","CVE-2026-54496"],"plain_summary":"GitHub lists this reviewed advisory for zebrad, halo2_gadgets, orchard, zcash_primitives. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-20b434e04e87ac502df4be859a021d4b"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-07-06T21:23:42.000Z","value":"9.3 critical","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-20b434e04e87ac502df4be859a021d4b"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-20b434e04e87ac502df4be859a021d4b","url":"https://github.com/advisories/GHSA-ww9q-8r59-xv46","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-ww9q-8r59-xv46","publisher":"GitHub Advisory Database","observed_at":"2026-11-04T23:36:01.427Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-20b434e04e87ac502df4be859a021d4b"],"technology":"zebrad","known_exclusions":[],"conditions_summary":"### Summary\n\nA soundness vulnerability in the variable-base scalar multiplication gadget of `halo2_gadgets` allowed a malicious prover to produce a valid proof for an Orchard Action with an *under-constrained* base point. Because this gadget enforces the diversified-address-integrity condition of the Orchard Action statement, the flaw let a prover satisfy that condition for an arbitrary (pkd, gd, ivk) triple, effectively bypassing the check that binds an Action to the correct incoming viewing key — and therefore to the correct nullifier (nf) and spend validating key (ak) — of the note being spent.\n\nThe main practical consequence is that an adversary could have performed a **double-spend within the Orchard pool**, resulting in a balance violation: the same note could be spent multiple times, each time revealing a distinct, valid-looking nullifier. The total ZEC supply was protected by Zcash's turnstile mechanism, which bounds value flowing out of any pool, so unbounded inflation of the overall supply was not possible; the exposure was inflation of value *within* the Orchard pool up to the turnstile-enforced limit.\n\nExploiting the vulnerability via a double-spen","public_affected_ranges":["<= 4.5.1"]},{"certainty":"source_listed","source_ids":["sr-20b434e04e87ac502df4be859a021d4b"],"technology":"halo2_gadgets","known_exclusions":[],"conditions_summary":"### Summary\n\nA soundness vulnerability in the variable-base scalar multiplication gadget of `halo2_gadgets` allowed a malicious prover to produce a valid proof for an Orchard Action with an *under-constrained* base point. Because this gadget enforces the diversified-address-integrity condition of the Orchard Action statement, the flaw let a prover satisfy that condition for an arbitrary (pkd, gd, ivk) triple, effectively bypassing the check that binds an Action to the correct incoming viewing key — and therefore to the correct nullifier (nf) and spend validating key (ak) — of the note being spent.\n\nThe main practical consequence is that an adversary could have performed a **double-spend within the Orchard pool**, resulting in a balance violation: the same note could be spent multiple times, each time revealing a distinct, valid-looking nullifier. The total ZEC supply was protected by Zcash's turnstile mechanism, which bounds value flowing out of any pool, so unbounded inflation of the overall supply was not possible; the exposure was inflation of value *within* the Orchard pool up to the turnstile-enforced limit.\n\nExploiting the vulnerability via a double-spen","public_affected_ranges":["< 0.5.0"]},{"certainty":"source_listed","source_ids":["sr-20b434e04e87ac502df4be859a021d4b"],"technology":"orchard","known_exclusions":[],"conditions_summary":"### Summary\n\nA soundness vulnerability in the variable-base scalar multiplication gadget of `halo2_gadgets` allowed a malicious prover to produce a valid proof for an Orchard Action with an *under-constrained* base point. Because this gadget enforces the diversified-address-integrity condition of the Orchard Action statement, the flaw let a prover satisfy that condition for an arbitrary (pkd, gd, ivk) triple, effectively bypassing the check that binds an Action to the correct incoming viewing key — and therefore to the correct nullifier (nf) and spend validating key (ak) — of the note being spent.\n\nThe main practical consequence is that an adversary could have performed a **double-spend within the Orchard pool**, resulting in a balance violation: the same note could be spent multiple times, each time revealing a distinct, valid-looking nullifier. The total ZEC supply was protected by Zcash's turnstile mechanism, which bounds value flowing out of any pool, so unbounded inflation of the overall supply was not possible; the exposure was inflation of value *within* the Orchard pool up to the turnstile-enforced limit.\n\nExploiting the vulnerability via a double-spen","public_affected_ranges":["< 0.14.0"]},{"certainty":"source_listed","source_ids":["sr-20b434e04e87ac502df4be859a021d4b"],"technology":"zcash_primitives","known_exclusions":[],"conditions_summary":"### Summary\n\nA soundness vulnerability in the variable-base scalar multiplication gadget of `halo2_gadgets` allowed a malicious prover to produce a valid proof for an Orchard Action with an *under-constrained* base point. Because this gadget enforces the diversified-address-integrity condition of the Orchard Action statement, the flaw let a prover satisfy that condition for an arbitrary (pkd, gd, ivk) triple, effectively bypassing the check that binds an Action to the correct incoming viewing key — and therefore to the correct nullifier (nf) and spend validating key (ak) — of the note being spent.\n\nThe main practical consequence is that an adversary could have performed a **double-spend within the Orchard pool**, resulting in a balance violation: the same note could be spent multiple times, each time revealing a distinct, valid-looking nullifier. The total ZEC supply was protected by Zcash's turnstile mechanism, which bounds value flowing out of any pool, so unbounded inflation of the overall supply was not possible; the exposure was inflation of value *within* the Orchard pool up to the turnstile-enforced limit.\n\nExploiting the vulnerability via a double-spen","public_affected_ranges":["< 0.28.0"]}],"null_published_at":"2026-11-05T19:10:21.415Z","source_updated_at":"2026-07-06T21:23:42.000Z","source_disclosed_at":"2026-07-06T21:23:41.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-04T23:36:01.427Z"}],"next_cursor":null,"snapshot_revision":"42594"}