CVE-2026-54496 json
Missing copy constraint in halo2_gadgets variable-base scalar multiplication allows under-constrained base, breaking Orchard Action circuit soundness
published 4mo ago modified 3mo ago also EUVD-2026-45228 , GHSA-ww9q-8r59-xv46
- cvss
- 9.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 24%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- crates.io zebrad 5.0.0
- crates.io halo2_gadgets 0.5.0
- crates.io orchard 0.14.0
- crates.io zcash_primitives 0.28.0
- z.cash zcash 6.20.0
- zfnd zebra-chain 5.0.0
- zfnd zebra-consensus 5.0.0
- zfnd zebra-network 5.0.0
- zfnd zebra-rpc 5.0.0
- zfnd zebra-script 5.0.0
- zfnd zebra 5.0.0
- zfnd zebrad 5.0.0
- github.com/ZcashFoundation/zebra/releases/tag/v5.0.0 release
- github.com/zcash/halo2/releases/tag/halo2_gadgets-0.5.0 release
- github.com/zcash/librustzcash/releases/tag/zcash_primitives-0.28.0 release
- github.com/zcash/orchard/releases/tag/0.14.0 release
- github.com/zcash/zcash/releases/tag/v6.20.0 release
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 3mo ago
Exploit prediction
0.32% chance of exploitation in the next 30 days, higher than 24% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 9.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:L |
| GitHub | 3.1 | 9.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:L |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| crates.io | zebrad | <5.0.0 |
5.0.0 |
| crates.io | halo2_gadgets | <0.5.0 |
0.5.0 |
| crates.io | orchard | <0.14.0 |
0.14.0 |
| crates.io | zcash_primitives | <0.28.0 |
0.28.0 |
Affected products
- ZcashFoundation zebra
- zcash halo2_gadgets
- zcash orchard
- zcash librustzcash
- zcash zcash
Classification
- Weakness
-
- CWE-345 Insufficient Verification of Data Authenticity
References
-
github.com
/ZcashFoundation/zebra/security/advisories/GHSA-ww9q-8r59-xv46
web
- github.com /ZcashFoundation/zebra/releases/tag/v5.0.0
- github.com /zcash/halo2/releases/tag/halo2_gadgets-0.5.0
- github.com /zcash/librustzcash/releases/tag/zcash_primitives-0.28.0
- github.com /zcash/orchard/releases/tag/0.14.0
- github.com /zcash/zcash/releases/tag/v6.20.0
- zfnd.org /zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation
-
github.com
/ZcashFoundation/zebra
package
Sources
- CVE List CVE-2026-54496
- GitHub Advisory GHSA-ww9q-8r59-xv46
- NVD CVE-2026-54496
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.