What’s Vulnerable › Vulnerabilities
CVE-2026-34208: SandboxJS: Sandbox integrity escape
- Severity: critical (CVSS 10.0 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.6% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2026-04-06 · updated 2026-10-26
- Weakness: CWE-693
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.
Affected products
- nyariv SandboxJS: before 0.8.36 — fixed in 0.8.36
How to fix
Upgrade to a fixed version: nyariv SandboxJS 0.8.36. Check the vendor advisory for mitigations.
References
Get alerted when CVE-2026-34208 or the next vulnerability affects your stack