CVE-2026-34208

CVE-2026-34208 · SandboxJS: Sandbox integrity escape

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 10.0 · Critical · EPSS 0.6% · Fix available

Published

2026-04-06T15:09:28.219Z

Updated

2026-04-06T18:39:14.717Z

Stack: node

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