CVE-2026-26954

SandboxJS has a Sandbox Escape

State: Published
Severity: 10.0 Critical
Published: Mar 13, 2026
Updated: Mar 16, 2026
Reserved: Feb 16, 2026

Description

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.34, it is possible to obtain arrays containing Function, which allows escaping the sandbox. Given an array containing Function, and Object.fromEntries, it is possible to construct {[p]: Function} where p is any constructible property. This vulnerability is fixed in 0.8.34.

Scores

CVSS	Score	Vector	Source
3.1	10.0 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H	GitHub_M

Weaknesses

CWE-94 Improper Control of Generation of Code ('Code Injection')

Affected Products

Product	Versions
SandboxJSnyariv	< 0.8.34Affected

References

https://github.com/nyariv/SandboxJS/security/advisories/GHSA-6r9f-759j-hjgv

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