CVE-2026-54496

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.

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