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Vulnerability record · CVE-2026-25586 · published 6 February 2026

CVE-2026-25586: Nyariv sandboxjs injection vulnerability

NNyariv · Sandboxjs

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.

10.0 CVSS 3.1 Critical EPSS 0.67% · top 50.0% CWE-74 · Injection
10.0CVSS 3.1 base score
0.67%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
3References, 2 tagged exploit
17 Jun 2026Last modified by NVD

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3 Patch
https://github.com/nyariv/SandboxJS/security/advisories/GHSA-jjpw-65fv-8g48 ExploitVendor Advisory
https://github.com/nyariv/SandboxJS/security/advisories/GHSA-jjpw-65fv-8g48 ExploitVendor Advisory

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-25586), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.