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TI-2026-21440 Aliases CVE-2026-26954GHSA-6r9f-759j-hjgv

SandboxJS has a Sandbox Escape

Priority HIGH 82CWE-94Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-94.

Summary

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.34, it is possible to obtain arrays containing Function, which allows escaping the sandbox. Given an array containing Function, and Object.fromEntries, it is possible to construct {[p]: Function} where p is any constructible property. This vulnerability is fixed in 0.8.34.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00569 47th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed SandboxJS (nyariv): 0.8.34@nyariv/sandboxjs (npm): 0.8.34

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
nyarivSandboxJSbefore 0.8.340.8.34Patch availableCNA
—@nyariv/sandboxjs (npm)before 0.8.340.8.34Patch availableGHSA-6r9f-759j-hjgv
  • SandboxJS Vendornyariv Affected before 0.8.34 Fixed in 0.8.34 Patch available CNA
  • @nyariv/sandboxjs (npm) Vendor— Affected before 0.8.34 Fixed in 0.8.34 Patch available GHSA-6r9f-759j-hjgv

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:nyariv:sandboxjs:*:*:*:*:*:node.js:*:*before 0.8.34Vulnerablenyariv
  • cpe:2.3:a:nyariv:sandboxjs:*:*:*:*:*:node.js:*:* Versions before 0.8.34 Vulnerable ·nyariv

Remediation

  • Fix · CNA SandboxJS (nyariv) Fixed in 0.8.34
  • Fix · GHSA-6r9f-759j-hjgv @nyariv/sandboxjs (npm) Fixed in 0.8.34 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-26954
  2. 2026-10-03 Alias added: GHSA-6r9f-759j-hjgv

References

Exploit 1

Advisory 1

Other 3

  • 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-2026-20741 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
  • TI-2026-20629 SandboxJS has a Sandbox Escape CVSS 3.1CRITICAL 10.0
See all 12 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences