SandboxJS is a JavaScript sandboxing library. Prior to 0.8.31, a sandbox escape vulnerability allows sandboxed code to mutate host built-in prototypes by laundering the isGlobal protection flag through array literal intermediaries. When a global prototype reference (e.g., Map.prototype, Set.prototype) is placed into an array and retrieved, the isGlobal taint is stripped, permitting direct prototype mutation from within the sandbox. This results in persistent host-side prototype pollution and may enable RCE in applications that use polluted properties in sensitive sinks (example gadget: execSync(obj.cmd)). This vulnerability is fixed in 0.8.31.
History

Mon, 09 Feb 2026 21:30:00 +0000

Type Values Removed Values Added
Description SandboxJS is a JavaScript sandboxing library. Prior to 0.8.31, a sandbox escape vulnerability allows sandboxed code to mutate host built-in prototypes by laundering the isGlobal protection flag through array literal intermediaries. When a global prototype reference (e.g., Map.prototype, Set.prototype) is placed into an array and retrieved, the isGlobal taint is stripped, permitting direct prototype mutation from within the sandbox. This results in persistent host-side prototype pollution and may enable RCE in applications that use polluted properties in sensitive sinks (example gadget: execSync(obj.cmd)). This vulnerability is fixed in 0.8.31.
Title @nyariv/sandboxjs has host prototype pollution from sandbox via array intermediary (sandbox escape)
Weaknesses CWE-1321
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-09T21:12:58.981Z

Reserved: 2026-02-06T21:08:39.129Z

Link: CVE-2026-25881

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-02-09T22:16:03.423

Modified: 2026-02-09T22:16:03.423

Link: CVE-2026-25881

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.