gnark commitments to private witnesses in Groth16 as implemented break zero-knowledge property

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.2 · CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2024-45040: 0.43% estimated exploitation activity in the next 30 days; percentile 37.02 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

This report concerns the Groth16 prover when used with commitments (as in frontend.Committer). To simplify exposition of the issue, I will focus on the case of a single commitment, to only private witnesses. But the issue should be present whenever commitments are used that include private witnesses. The commitment to private witnesses wi is computed as where bi would be ProvingKey.CommitmentKeys[0].Basis[i] in the code. While this is a binding commitment, it is not hiding. In practice, an adversary will know the points bi, as they are part of the proving key, and can verify correctness of a guess for the values of wi by computing c' as the right hand side of the above formula, and checking whether c' is equal to c. I attach a proof of concept that demonstrates this. This breaks the perfect zero-knowledge property of Groth16, so the Groth16 scheme using commitments to private witnesses as implemented by gnark fails to be a zk-SNARK. The code indicates that the extension to Groth16…

Published by the source

6 Sep 2024, 19:40 UTC

Last modified by the source

18 Nov 2024, 16:27 UTC

Source last checked

26 Oct 2026, 15:08 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-9xcg-3q8v-7fq6

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# Patch Next advisory brief: CVE-2024-45040

Advisory: gnark commitments to private witnesses in Groth16 as implemented break zero-knowledge property
IDs: CVE-2024-45040, GHSA-9xcg-3q8v-7fq6
Record: https://patchnext.com/advisories/cve-2024-45040 (revision 1, source checked 26 Oct 2026, 15:08 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/consensys/gnark 0.11.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/consensys/gnark: affected < 0.11.0; fixed in 0.11.0

## Suggested inspection (read-only)
- Go github.com/consensys/gnark: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/consensys/gnark.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-9xcg-3q8v-7fq6 (GitHub-reviewed advisory GHSA-9xcg-3q8v-7fq6 lists affected ranges: Go github.com/consensys/gnark >=0 <0.11.0)

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