CVE-2025-57801: gnark is vulnerable to signature malleability in EdDSA and ECDSA due to missing scalar checks

Severity: critical (CVSS 9.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2025-08-22 · updated 2026-06-17
Weakness: CWE-347

Description

gnark is a zero-knowledge proof system framework. In versions prior to 0.14.0, the Verify function in eddsa.go and ecdsa.go used the S value from a signature without asserting that 0 ≤ S < order, leading to a signature malleability vulnerability. Because gnark’s native EdDSA and ECDSA circuits lack essential constraints, multiple distinct witnesses can satisfy the same public inputs. In protocols where nullifiers or anti-replay checks are derived from R and S, this enables signature malleability and may allow double spending. This issue has been addressed in version 0.14.0.

Affected products

Consensys gnark: before 0.14.0 — fixed in 0.14.0

How to fix

Upgrade to a fixed version: Consensys gnark 0.14.0. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2025-57801 or the next vulnerability affects your stack