SandboxJS: Stack overflow DoS via deeply nested expressions in recursive descent parser
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-674.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| nyariv | SandboxJS | before 0.8.36 | 0.8.36 | Patch available | CNA |
| — | @nyariv/sandboxjs (npm) | before 0.8.36 | 0.8.36 | Patch available | GHSA-8pfc-jjgw-6g26 |
- SandboxJS Vendornyariv Affected before 0.8.36 Fixed in 0.8.36 Patch available CNA
- @nyariv/sandboxjs (npm) Vendor— Affected before 0.8.36 Fixed in 0.8.36 Patch available GHSA-8pfc-jjgw-6g26
Remediation
- Fix · CNA SandboxJS (nyariv) Fixed in 0.8.36
- Fix · GHSA-8pfc-jjgw-6g26 @nyariv/sandboxjs (npm) Fixed in 0.8.36 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-34211
- 2026-10-03 Alias added: GHSA-8pfc-jjgw-6g26
References
More nyariv Sandboxjs vulnerabilities
- TI-2026-31962 SandboxJS: Sandbox escape via Function.caller leakage of internal call op CVSS 3.1CRITICAL 10.0
- TI-2026-26503 SandboxJS: Sandbox integrity escape CVSS 3.1CRITICAL 10.0
- TI-2026-21440 SandboxJS has a Sandbox Escape CVSS 3.1CRITICAL 10.0
- TI-2026-20741 SandboxJS has a sandbox escape via TOCTOU bug on keys in property accesses CVSS 3.1CRITICAL 10.0
- TI-2026-20694 SandboxJS has a Sandbox Escape CVSS 3.1CRITICAL 10.0
- TI-2026-20693 SandboxJS has a Sandbox Escape via Prototype Whitelist Bypass and Host Prototype Pollution CVSS 3.1CRITICAL 10.0
Sources
- CVE-2026-34211 · CVE Program
- CVE-2026-34211 · NVD
- FIRST EPSS
- GHSA-8pfc-jjgw-6g26 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences