gnark-crypto's exponentiation in the pairing target group GT using GLV can give incorrect results

Exploitation

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

CVSS

not scored

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Impact When the exponent is bigger than r, the group order of the pairing target group GT, the exponentiation à la GLV (ExpGLV) can sometimes give incorrect results compared to normal exponentiation (Exp). The issue impacts all users using ExpGLV for exponentiations in GT. This does not impact Exp and ExpCyclotomic which are sound. Also note that GLV methods in G1 and G2 are sound and not impacted. Patches Fix has been implemented in pull request https://github.com/Consensys/gnark-crypto/pull/451 and merged in commit https://github.com/Consensys/gnark-crypto/commit/ec6be1a037f7c496d595c541a8a8d31c47bcfa3d to master branch. The fix increased the bounds of the sub-scalars by 1. In fact, since https://github.com/Consensys/gnark-crypto/pull/213, we use a fast scalar decomposition that tradeoffs divisions (needed in the Babai rounding) by right-shifts. We precompute b=2^mv/d (m log2(d)) and then at runtime compute scalarb/2^m (v is a lattice vector and d the lattice determinant). This…

Published by the source

5 Oct 2023, 20:57 UTC

Last modified by the source

8 Nov 2023, 18:36 UTC

Source last checked

26 Oct 2026, 15:00 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-pffg-92cg-xf5c

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# Patch Next advisory brief: GHSA-pffg-92cg-xf5c

Advisory: gnark-crypto's exponentiation in the pairing target group GT using GLV can give incorrect results
IDs: GHSA-pffg-92cg-xf5c
Record: https://patchnext.com/advisories/ghsa-pffg-92cg-xf5c (revision 1, source checked 26 Oct 2026, 15:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
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-crypto 0.12.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/consensys/gnark-crypto: affected <= 0.12.0; fixed in 0.12.1

## Suggested inspection (read-only)
- Go github.com/consensys/gnark-crypto: 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-crypto.
- 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-pffg-92cg-xf5c (GitHub-reviewed advisory GHSA-pffg-92cg-xf5c lists affected ranges: Go github.com/consensys/gnark-crypto >=0 <=0.12.0)

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