CVE-2026-34211

SandboxJS: Stack overflow DoS via deeply nested expressions in recursive descent parser

State: Published
Severity: 6.9 Medium
Published: Apr 6, 2026
Updated: Apr 7, 2026
Reserved: Mar 26, 2026

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.

Scores

CVSS	Score	Vector	Source
4.0	6.9 Medium	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N	GitHub_M
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	CISA-ADP

Weaknesses

CWE-674 Uncontrolled Recursion

Affected Products

Product	Versions
SandboxJSnyariv	< 0.8.36Affected

References

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

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