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TI-2026-26503 Aliases CVE-2026-34208GHSA-2gg9-6p7w-6cpj

SandboxJS: Sandbox integrity escape

Priority HIGH 82CWE-693Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass, Tampering
Confidentiality · integrity · availability
High · High · Low
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-693 and CWE-915.

Summary

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.36, SandboxJS blocks direct assignment to global objects (for example Math.random = ...), but this protection can be bypassed through an exposed callable constructor path: this.constructor.call(target, attackerObject). Because this.constructor resolves to the internal SandboxGlobal function and Function.prototype.call is allowed, attacker code can write arbitrary properties into host global objects and persist those mutations across sandbox instances in the same process. This vulnerability is fixed in 0.8.36.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00581 48th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed SandboxJS (nyariv): 0.8.36@nyariv/sandboxjs (npm): 0.8.36

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 0.8.360.8.36Patch availableCNA
—@nyariv/sandboxjs (npm)before 0.8.360.8.36Patch availableGHSA-2gg9-6p7w-6cpj
  • 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-2gg9-6p7w-6cpj

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:nyariv:sandboxjs:*:*:*:*:*:node.js:*:*before 0.8.36Vulnerablenyariv
  • cpe:2.3:a:nyariv:sandboxjs:*:*:*:*:*:node.js:*:* Versions before 0.8.36 Vulnerable ·nyariv

Remediation

  • Fix · CNA SandboxJS (nyariv) Fixed in 0.8.36
  • Fix · GHSA-2gg9-6p7w-6cpj @nyariv/sandboxjs (npm) Fixed in 0.8.36 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34208
  2. 2026-10-03 Alias added: GHSA-2gg9-6p7w-6cpj

References

Exploit 1

Advisory 1

Other 1

  • TI-2026-31962 SandboxJS: Sandbox escape via Function.caller leakage of internal call op 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
  • 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