GHSA-fr8m-434r-g3xp is a medium-severity (CVSS 5.1) Deserialization of Untrusted Data vulnerability in github.com/consensys/gnark-crypto. A fix is available for github.com/consensys/gnark-crypto — see the affected versions and patch details below.
gnark-crypto doesn't range check input values during ECDSA and EdDSA signature deserialization
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-fr8m-434r-g3xp.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-fr8m-434r-g3xp plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/consensys/gnark-cryptoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
During deserialization of ECDSA and EdDSA signatures gnark-crypto did not check that the values are in the range [1, n-1] with n being the corresponding modulus (either base field modulus in case of R in EdDSA, and scalar field modulus in case of s,r in ECDSA and s in EdDSA). As this also allowed zero inputs, then it was possible to craft a signature which lead to null pointer dereference, leading to denial-of-service of an application. This also enabled weak signature malleability when the users assumed uniqueness of the serialized signatures (but not the underlying modulo reduced values).
We are not aware of any users impacted by the bug. The implemented signature schemes in gnark-crypto complement the in-circuit versions in gnark, allowing to have end-to-end tests.
Patches
The issue was patched in PR #449. The fix returns an error during deserialization if the values do not belong to the ranges [1, n-1].
The fix is included in release v0.12.0 and upwards.
Workarounds
Users can manually validate the inputs to be in corresponding ranges when using serialized signatures (or digests of them) as unique keys.
To address the denial-of-service, the users can install hook to recover panics and recover
Resources
- Verichains advisory for signature malleability.
- Fix https://github.com/Consensys/gnark-crypto/pull/449
- Go blog post "Defer, Panic, and Recover"
- gnark v0.12.0
Acknowledgement
Lack of range checks leading to signature malleability was reported by Verichains.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/consensys/gnark-crypto | all versions | 0.12.0go get github.com/consensys/gnark-crypto@v0.12.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/consensys/gnark-crypto, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/consensys/gnark-crypto to 0.12.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fr8m-434r-g3xp is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-fr8m-434r-g3xp can be triaged on real exposure rather than presence alone.
Tailored to GHSA-fr8m-434r-g3xp. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-fr8m-434r-g3xp in your dependencies?
O3 Security finds GHSA-fr8m-434r-g3xp across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.