Zcash Foundation Zebra prior 5.0.0/0.5.0/0.14.0/0.28.0/6.20.0 Scalar Multiplication Gadget incomplete.rs assign_advice integrity check

Summaryinfo

A vulnerability categorized as critical has been discovered in Zcash Foundation Zebra. Affected is the function assign_advice of the file halo2_gadgets/src/ecc/chip/mul/incomplete.rs of the component Scalar Multiplication Gadget. The manipulation results in integrity check. This vulnerability is cataloged as CVE-2026-54496. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as critical, was found in Zcash Foundation Zebra. Affected is the function assign_advice of the file halo2_gadgets/src/ecc/chip/mul/incomplete.rs of the component Scalar Multiplication Gadget. The manipulation with an unknown input leads to a integrity check vulnerability. CWE is classifying the issue as CWE-354. The product does not validate or incorrectly validates the integrity check values or "checksums" of a message. This may prevent it from detecting if the data has been modified or corrupted in transmission. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-54496 since 06/15/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available.

Upgrading to version 5.0.0, 0.5.0, 0.14.0, 0.28.0 or 6.20.0 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• Zcash Foundation

Name

• Zebra

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Once again VulDB remains the best source for vulnerability data.

Discussion