What is CVE-2026-34211?

CVE-2026-34211 is a high-severity vulnerability in Nyariv Sandboxjs, classified under Uncontrolled Recursion. CVSS score: 7.5/10. Published 2026-04-06.

How severe is CVE-2026-34211?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Nyariv Sandboxjs

CVE-2026-34211

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.36, the @nyariv/sandboxjs parser contains unbounded recursion in the restOfExp function and the lispify/lispifyExpr call chain. An attacker can crash any Node.js process that parse…

EPSS: 0.004 (31.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Nyariv Sandboxjs — versions < 0.8.36

Weakness classification (CWE)

CWE-674 — Uncontrolled Recursion

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2026-34211?: CVE-2026-34211 is a high-severity vulnerability in Nyariv Sandboxjs, classified under Uncontrolled Recursion. CVSS score: 7.5/10. Published 2026-04-06.
How severe is CVE-2026-34211?: High severity. CVSS v3 base score is 7.5 out of 10.