CVE-2026-54496

ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad 5.0.0, halo2gadgets 0.5.0, orchard 0.14.0, zcashprimitives 0.28.0, and zcashd 6.20.0, the variable-base scalar multiplication gadget in halo2gadgets/src/ecc/chip/mul/incomplete.rs used assignadvice() 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 pkd, gd, ivk, the nullifier (nf), and the spend validating key (ak) to the note being spent. This issue is fixed in zebrad 5.0.0, halo2gadgets 0.5.0, orchard 0.14.0, zcashprimitives 0.28.0, and zcashd 6.20.0.