SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, a sandbox escape is possible by shadowing hasOwnProperty on a sandbox object, which disables prototype whitelist enforcement in the property-access path. This permits direct access to __proto__ and other blocked prototype properties, enabling host Object.prototype pollution and persistent cross-sandbox impact. This vulnerability is fixed in 0.8.29.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-jjpw-65fv-8g48 @nyariv/sandboxjs has Sandbox Escape via Prototype Whitelist Bypass and Host Prototype Pollution
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 06 Feb 2026 21:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 06 Feb 2026 20:00:00 +0000

Type Values Removed Values Added
Description SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, a sandbox escape is possible by shadowing hasOwnProperty on a sandbox object, which disables prototype whitelist enforcement in the property-access path. This permits direct access to __proto__ and other blocked prototype properties, enabling host Object.prototype pollution and persistent cross-sandbox impact. This vulnerability is fixed in 0.8.29.
Title SandboxJS has a Sandbox Escape via Prototype Whitelist Bypass and Host Prototype Pollution
Weaknesses CWE-74
References
Metrics cvssV3_1

{'score': 10, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-06T20:17:19.095Z

Reserved: 2026-02-03T01:02:46.715Z

Link: CVE-2026-25586

cve-icon Vulnrichment

Updated: 2026-02-06T20:17:03.787Z

cve-icon NVD

Status : Undergoing Analysis

Published: 2026-02-06T20:16:10.770

Modified: 2026-02-06T21:57:22.450

Link: CVE-2026-25586

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses