GHSA-4g63-c64m-25w9 is a high-severity (CVSS 7.5) Improper Input Validation vulnerability in @openzeppelin/contracts. A fix is available for @openzeppelin/contracts — see the affected versions and patch details below.
OpenZeppelin Contracts's SignatureChecker may revert on invalid EIP-1271 signers
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.
- 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-4g63-c64m-25w9.
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-4g63-c64m-25w9 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 377,166 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
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@openzeppelin/contractsnpm@openzeppelin/contracts-upgradeablenpmDescription
Impact
SignatureChecker.isValidSignatureNow is not expected to revert. However, an incorrect assumption about Solidity 0.8's abi.decode allows some cases to revert, given a target contract that doesn't implement EIP-1271 as expected.
The contracts that may be affected are those that use SignatureChecker to check the validity of a signature and handle invalid signatures in a way other than reverting. We believe this to be unlikely.
Patches
The issue was patched in 4.7.1.
References
https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3552
For more information
If you have any questions or comments about this advisory, or need assistance deploying the fix, email us at [email protected].
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @openzeppelin/contracts | ≥ 4.1.0&&< 4.7.1 | 4.7.1npm install @openzeppelin/contracts@4.7.1 |
| 📦npm | @openzeppelin/contracts-upgradeable | ≥ 4.1.0&&< 4.7.1 | 4.7.1npm install @openzeppelin/contracts-upgradeable@4.7.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @openzeppelin/contracts, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @openzeppelin/contracts to 4.7.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4g63-c64m-25w9 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-4g63-c64m-25w9 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-4g63-c64m-25w9. 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-4g63-c64m-25w9 in your dependencies?
O3 Security finds GHSA-4g63-c64m-25w9 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.