SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, there is a sandbox escape vulnerability due to a mismatch between the key on which the validation is performed and the key used for accessing properties. Even though the key used in property accesses is annotated as string, this is never enforced. So, attackers can pass malicious objects that coerce to different string values when used, e.g., one for the time the key is sanitized using hasOwnProperty(key) and a different one for when the key is used for the actual property access. This vulnerability is fixed in 0.8.29.
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, there is a sandbox escape vulnerability due to a mismatch between the key on which the validation is performed and the key used for accessing properties. Even though the key used in property accesses is annotated as string, this is never enforced. So, attackers can pass malicious objects that coerce to different string values when used, e.g., one for the time the key is sanitized using hasOwnProperty(key) and a different one for when the key is used for the actual property access. This vulnerability is fixed in 0.8.29.
Title SandboxJS has a sandbox escape via TOCTOU bug on keys in property accesses
Weaknesses CWE-367
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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-06T20:20:03.764Z

Reserved: 2026-02-04T05:15:41.791Z

Link: CVE-2026-25641

cve-icon Vulnrichment

Updated: 2026-02-06T20:19:51.117Z

cve-icon NVD

Status : Received

Published: 2026-02-06T20:16:11.263

Modified: 2026-02-06T21:16:19.023

Link: CVE-2026-25641

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.