Vulnerability 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.
CVSS Score
CRITICAL
Related Weaknesses (CWE)
References
- https://github.com/ZcashFoundation/zebra/releases/tag/v5.0.0
- https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-ww9q-8r59-xv46
- 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
FAQ
What is CVE-2026-54496?
CVE-2026-54496 is a vulnerability with a CVSS score of 9.3 (CRITICAL). 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 i...
How severe is CVE-2026-54496?
CVE-2026-54496 has been rated CRITICAL with a CVSS base score of 9.3/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-54496?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.