What is CVE-2026-34208?

CVE-2026-34208 is a critical-severity vulnerability in Nyariv Sandboxjs, classified under Protection Mechanism Failure. CVSS score: 10.0/10. Published 2026-04-06.

How severe is CVE-2026-34208?

Critical severity. CVSS v3 base score is 10.0 out of 10.

Vulnerability in Nyariv Sandboxjs

CVE-2026-34208

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.con…

EPSS: 0.003 (50.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L.

Affected products

Nyariv Sandboxjs — versions < 0.8.36

Weakness classification (CWE)

CWE-693 — Protection Mechanism Failure
CWE-915 — Improperly Controlled Modification of Dynamically-Determined Object Attributes

References

https://github.com/nyariv/SandboxJS/security/advisories/GHSA-2gg9-6p7w-6cpj (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-34208?: CVE-2026-34208 is a critical-severity vulnerability in Nyariv Sandboxjs, classified under Protection Mechanism Failure. CVSS score: 10.0/10. Published 2026-04-06.
How severe is CVE-2026-34208?: Critical severity. CVSS v3 base score is 10.0 out of 10.