CVE-2026-54496 Missing copy constraint in halo2_gadgets variable-base scalar multiplication allows under-constrained base, breaking Orchard Action circuit soundness

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...

GHSA-WW9Q-8R59-XV46 Zebra: Missing copy constraint in halo2_gadgets variable-base scalar multiplication allows under-constrained base, breaking Orchard Action circuit soundness

Summary A soundness vulnerability in the variable-base scalar multiplication gadget of halo2gadgets allowed a malicious prover to produce a valid proof for an Orchard Action with an under-constrained base point. Because this gadget enforces the diversified-address-integrity condition of the Orcha...