Vulnerability · Published Apr 6, 2026 · Assigned by GitHub_M

CVE-2026-34211SandboxJS: Stack overflow DoS via deeply nested expressions in recursive descent parser

High 7.5

In plain English

A high-severity security flaw in SandboxJS from nyariv. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.4%top 64.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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 parses untrusted input by supplying deeply nested expressions (e.g., ~2000 nested parentheses), causing a RangeError: Maximum call stack size exceeded that terminates the process. This vulnerability is fixed in 0.8.36.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	@nyariv/sandboxjs	0.8.36	GHSA-8pfc-jjgw-6g26

Affected products (as reported)

Vendor	Product	Versions
nyariv	SandboxJS	< 0.8.36

Weakness: CWE-674 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

https://github.com/nyariv/SandboxJS/security/advisories/GHSA-8pfc-jjgw-6g26 x_refsource_CONFIRM