SandboxJS: Sandbox integrity escape_CVE-2026-34208

10 / 10

CRITICAL

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

Description

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.36, SandboxJS blocks direct assignment to global objects (for example Math.random = ...), but this protection can be bypassed through an exposed callable constructor path: this.constructor.call(target, attackerObject). Because this.constructor resolves to the internal SandboxGlobal function and Function.prototype.call is allowed, attacker code can write arbitrary properties into host global objects and persist those mutations across sandbox instances in the same process. This vulnerability is fixed in 0.8.36.

Basic Information

ID CVE-2026-34208

Source GitHub_M

Published Apr 6, 2026 at 15:09

Modified Apr 6, 2026 at 18:39

Affected Product

Vendor nyariv

Product SandboxJS

Version < 0.8.36

Affected Versions nyariv SandboxJS < 0.8.36

CWE Classification

CWE-693 CWE-915

References

github.com /nyariv/SandboxJS/security/advisories/GHSA-2gg9-6p7w-6cpj

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