{"id":"CVE-2026-54496","state":"PUBLISHED","title":"Missing copy constraint in halo2_gadgets variable-base scalar multiplication allows under-constrained base, breaking Orchard Action circuit soundness","description":"ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad 5.0.0, halo2_gadgets 0.5.0, orchard 0.14.0, zcash_primitives 0.28.0, and zcashd 6.20.0, the variable-base scalar multiplication gadget in halo2_gadgets/src/ecc/chip/mul/incomplete.rs used assign_advice() for the base point without a copy constraint tying it to the actual base, allowing a malicious prover to produce a valid proof for an Orchard Action with an under-constrained base point and bypass the diversified-address-integrity check that binds pk_d, g_d, ivk, the nullifier (nf), and the spend validating key (ak) to the note being spent. This issue is fixed in zebrad 5.0.0, halo2_gadgets 0.5.0, orchard 0.14.0, zcash_primitives 0.28.0, and zcashd 6.20.0.","publishedAt":"2026-07-17T16:59:06.809Z","updatedAt":"2026-07-17T17:23:50.731Z","severity":{"score":9.3,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["ZcashFoundation zebra","zcash halo2_gadgets","zcash orchard","zcash librustzcash","zcash zcash"],"affected":[{"vendor":"ZcashFoundation","product":"zebra","versions":[{"version":"< 5.0.0","status":"affected"}]},{"vendor":"zcash","product":"halo2_gadgets","versions":[{"version":"< 0.5.0","status":"affected"}]},{"vendor":"zcash","product":"orchard","versions":[{"version":"< 0.14.0","status":"affected"}]},{"vendor":"zcash","product":"librustzcash","versions":[{"version":"< 0.28.0","status":"affected"}]},{"vendor":"zcash","product":"zcash","versions":[{"version":"< 6.20.0","status":"affected"}]}],"references":["https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-ww9q-8r59-xv46","https://github.com/ZcashFoundation/zebra/releases/tag/v5.0.0","https://github.com/zcash/halo2/releases/tag/halo2_gadgets-0.5.0","https://github.com/zcash/librustzcash/releases/tag/zcash_primitives-0.28.0","https://github.com/zcash/orchard/releases/tag/0.14.0","https://github.com/zcash/zcash/releases/tag/v6.20.0","https://zfnd.org/zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation"],"weaknesses":["CWE-345"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/54xxx/CVE-2026-54496.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-54496","state":"PUBLISHED","datePublished":"2026-07-17T16:59:06.809Z","dateUpdated":"2026-07-17T17:23:50.731Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-15T18:01:15.511Z"},"containers":{"cna":{"title":"Missing copy constraint in halo2_gadgets variable-base scalar multiplication allows under-constrained base, breaking Orchard Action circuit soundness","descriptions":[{"lang":"en","value":"ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad 5.0.0, halo2_gadgets 0.5.0, orchard 0.14.0, zcash_primitives 0.28.0, and zcashd 6.20.0, the variable-base scalar multiplication gadget in halo2_gadgets/src/ecc/chip/mul/incomplete.rs used assign_advice() for the base point without a copy constraint tying it to the actual base, allowing a malicious prover to produce a valid proof for an Orchard Action with an under-constrained base point and bypass the diversified-address-integrity check that binds pk_d, g_d, ivk, the nullifier (nf), and the spend validating key (ak) to the note being spent. This issue is fixed in zebrad 5.0.0, halo2_gadgets 0.5.0, orchard 0.14.0, zcash_primitives 0.28.0, and zcashd 6.20.0."}],"affected":[{"vendor":"ZcashFoundation","product":"zebra","versions":[{"version":"< 5.0.0","status":"affected"}]},{"vendor":"zcash","product":"halo2_gadgets","versions":[{"version":"< 0.5.0","status":"affected"}]},{"vendor":"zcash","product":"orchard","versions":[{"version":"< 0.14.0","status":"affected"}]},{"vendor":"zcash","product":"librustzcash","versions":[{"version":"< 0.28.0","status":"affected"}]},{"vendor":"zcash","product":"zcash","versions":[{"version":"< 6.20.0","status":"affected"}]}],"references":[{"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-ww9q-8r59-xv46","name":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-ww9q-8r59-xv46","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/ZcashFoundation/zebra/releases/tag/v5.0.0","name":"https://github.com/ZcashFoundation/zebra/releases/tag/v5.0.0","tags":["x_refsource_MISC"]},{"url":"https://github.com/zcash/halo2/releases/tag/halo2_gadgets-0.5.0","name":"https://github.com/zcash/halo2/releases/tag/halo2_gadgets-0.5.0","tags":["x_refsource_MISC"]},{"url":"https://github.com/zcash/librustzcash/releases/tag/zcash_primitives-0.28.0","name":"https://github.com/zcash/librustzcash/releases/tag/zcash_primitives-0.28.0","tags":["x_refsource_MISC"]},{"url":"https://github.com/zcash/orchard/releases/tag/0.14.0","name":"https://github.com/zcash/orchard/releases/tag/0.14.0","tags":["x_refsource_MISC"]},{"url":"https://github.com/zcash/zcash/releases/tag/v6.20.0","name":"https://github.com/zcash/zcash/releases/tag/v6.20.0","tags":["x_refsource_MISC"]},{"url":"https://zfnd.org/zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation","name":"https://zfnd.org/zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":9.3,"baseSeverity":"CRITICAL","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-345","lang":"en","description":"CWE-345: Insufficient Verification of Data Authenticity","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-17T16:59:06.809Z"},"source":{"advisory":"GHSA-ww9q-8r59-xv46","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-17T17:23:34.445671Z","id":"CVE-2026-54496","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-17T17:23:50.731Z"}}]}}}