Description
vm2 is a sandbox for running untrusted JavaScript. In vm2 versions up to and including 3.11.3, the defaultSandboxPrepareStackTrace function in lib/setup-sandbox.js builds its output array using prototype-walking index assignment (lines[lines.length] = value) rather than a prototype-bypassing define-property primitive. Because this bridge-internal array is allocated in the sandbox realm, code inside the sandbox can install an accessor on Array.prototype for the relevant index; the accessor is then invoked whenever the sandbox reads error.stack (or otherwise triggers Error.prepareStackTrace), allowing sandbox code to observe and intercept each stack-trace line written by the bridge. The same pattern is used in the error-handling (catch) branch. The values written are formatted strings only, so the practical impact is limited to an information side channel and a violation of vm2's bridge-container defense invariant rather than a sandbox escape; the vendor rates the issue Low. The issue is fixed in vm2 3.11.4, which installs each entry as an own data property via Reflect.defineProperty.
Published: 2026-09-17
Score: 2.1 Low
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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History

Thu, 17 Sep 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 17 Sep 2026 14:00:00 +0000

Type Values Removed Values Added
Description vm2 is a sandbox for running untrusted JavaScript. In vm2 versions up to and including 3.11.3, the defaultSandboxPrepareStackTrace function in lib/setup-sandbox.js builds its output array using prototype-walking index assignment (lines[lines.length] = value) rather than a prototype-bypassing define-property primitive. Because this bridge-internal array is allocated in the sandbox realm, code inside the sandbox can install an accessor on Array.prototype for the relevant index; the accessor is then invoked whenever the sandbox reads error.stack (or otherwise triggers Error.prepareStackTrace), allowing sandbox code to observe and intercept each stack-trace line written by the bridge. The same pattern is used in the error-handling (catch) branch. The values written are formatted strings only, so the practical impact is limited to an information side channel and a violation of vm2's bridge-container defense invariant rather than a sandbox escape; the vendor rates the issue Low. The issue is fixed in vm2 3.11.4, which installs each entry as an own data property via Reflect.defineProperty.
Title vm2 before 3.11.4 Defense Invariant Violation via setup-sandbox.js
Weaknesses CWE-693
References
Metrics cvssV4_0

{'score': 2.1, 'vector': 'CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-09-17T15:40:44.491Z

Reserved: 2026-09-17T12:43:31.527Z

Link: CVE-2026-92962

cve-icon Vulnrichment

Updated: 2026-09-17T15:40:41.331Z

cve-icon NVD

Status : Deferred

Published: 2026-09-17T14:18:02.610

Modified: 2026-09-17T16:18:34.940

Link: CVE-2026-92962

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses