CVE-2026-54496
Missing copy constraint in halo2_gadgets variable-base scalar multiplication allows under-constrained base, breaking Orchard Action circuit soundness
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.
INFO
Published Date :
July 17, 2026, 5:17 p.m.
Last Modified :
July 17, 2026, 6:45 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-54496
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | [email protected] |
Solution
- Update zebrad to version 5.0.0 or later.
- Update halo2_gadgets to version 0.5.0 or later.
- Update orchard to version 0.14.0 or later.
- Update zcash_primitives to version 0.28.0 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-54496.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-54496 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-54496
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-54496 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-54496 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-54496', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-17T17:23:34.445671Z'} -
New CVE Received by [email protected]
Jul. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'ZcashFoundation', 'product': 'zebra', 'versions': [{'status': 'affected', 'version': '< 5.0.0'}]}, {'vendor': 'zcash', 'product': 'halo2_gadgets', 'versions': [{'status': 'affected', 'version': '< 0.5.0'}]}, {'vendor': 'zcash', 'product': 'orchard', 'versions': [{'status': 'affected', 'version': '< 0.14.0'}]}, {'vendor': 'zcash', 'product': 'librustzcash', 'versions': [{'status': 'affected', 'version': '< 0.28.0'}]}, {'vendor': 'zcash', 'product': 'zcash', 'versions': [{'status': 'affected', 'version': '< 6.20.0'}]}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:L Added CWE CWE-345 Added Reference https://github.com/zcash/halo2/releases/tag/halo2_gadgets-0.5.0 Added Reference https://github.com/zcash/librustzcash/releases/tag/zcash_primitives-0.28.0 Added Reference https://github.com/zcash/orchard/releases/tag/0.14.0 Added Reference https://github.com/zcash/zcash/releases/tag/v6.20.0 Added Reference https://github.com/ZcashFoundation/zebra/releases/tag/v5.0.0 Added Reference https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-ww9q-8r59-xv46 Added Reference https://zfnd.org/zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation