GHSA-75jp-vq8x-h4cq is a high-severity (CVSS 7.3) Out-of-bounds Write vulnerability in wasmi. A fix is available for wasmi — see the affected versions and patch details below.
Wasmi Out-of-bounds Write for host to Wasm calls with more than 128 Parameters
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-75jp-vq8x-h4cq.
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-75jp-vq8x-h4cq 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 378,567 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
wasmiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Summary
In the WASMI Interpreter, an Out-of-bounds Buffer Write will arise arise if the host calls or resumes a Wasm function with more parameters than the default limit (128), as it will surpass the stack value. This doesn’t affect calls from Wasm to Wasm, only from host to Wasm.
Impact
After conducting an analysis of the dependent Polkadot systems of wasmi: Pallet Contracts, Parity Signer, and Smoldot, we have found that none on those systems have been affected by the issue as they are calling host to Wasm function with a small limited amount of parameters always.
Mitigations
If you are using wasmi betwen version 0.15.0 and 0.31.0, please update it to the 0.31.1 patch release that we just published.
Workarounds
Ensure no more than 128 parameters can be pass in a call from the host to a Wasm function.
References
Patch PR: <PR>
Special thanks
Special thanks to Stellar Development Foundation for reporting this security vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | wasmi | ≥ 0.15.0&&< 0.31.1 | 0.31.1cargo update -p wasmi --precise 0.31.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for wasmi, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update wasmi to 0.31.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-75jp-vq8x-h4cq 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-75jp-vq8x-h4cq can be triaged on real exposure rather than presence alone.
Tailored to GHSA-75jp-vq8x-h4cq. 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-75jp-vq8x-h4cq in your dependencies?
O3 Security finds GHSA-75jp-vq8x-h4cq across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.