RUSTSEC-2025-0129: Missing check in ZK proof in CGGMP21 Threshold Signing Protocol

What to do

1. See which version you have: cargo tree -i cggmp21 (it also shows which of your dependencies pulls it in).
2. Update within your version requirement: cargo update -p cggmp21. If the fix is a newer major or minor than your requirement allows, raise it in Cargo.toml (for example cggmp21 = "0.6.3") or update the dependency that pulls it in.
3. Check again with cargo audit, or paste your Cargo.lock into our Cargo.toml checker.

Details from the advisory

Vulnerability concerns a missing check in the ZK proof that enables an attack in which single malicious signer can reconstruct full private key.

Patches

• cggmp21 v0.6.3 is a patch release that contains a fix that introduces this specific missing check.
• However, we recommend upgrading to cggmp24 v0.7.0-alpha.2 in which we've introduced many other security checks as a precaution. Follow the migration guidelines to upgrade.

References

Read our blog post to learn more.

References

• Package: crates.io/crates/cggmp21
• Advisory: rustsec.org/advisories/RUSTSEC-2025-0129.html
• Web: www.dfns.co/article/cggmp21-vulnerabilities-patched-and-explained

From the RustSec Advisory Database (CC0-1.0) via the OSV export, downloaded Oct 24, 2026. Severity score computed from the published CVSS vector.

Other advisories for cggmp21

• VulnerabilityRUSTSEC-2024-0393 · 2024-07-18Ambiguous challenge derivation
• VulnerabilityRUSTSEC-2025-0127 · 2025-11-24CGGMP21 presignatures can be used in the way that significantly reduces security

Full security history of cggmp21