# CVE-2026-25881

## Summary

- **CVE ID:** CVE-2026-25881
- **Severity:** CRITICAL
- **CVSS Score:** 9.1 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H)
- **CWE:** CWE-1321
- **Published:** Feb 9, 2026
- **Last Modified:** Mar 12, 2026

## Description

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.31, a sandbox escape vulnerability allows sandboxed code to mutate host built-in prototypes by laundering the isGlobal protection flag through array literal intermediaries. When a global prototype reference (e.g., Map.prototype, Set.prototype) is placed into an array and retrieved, the isGlobal taint is stripped, permitting direct prototype mutation from within the sandbox. This results in persistent host-side prototype pollution and may enable RCE in applications that use polluted properties in sensitive sinks (example gadget: execSync(obj.cmd)). This vulnerability is fixed in 0.8.31.

## Affected Products

- nyariv — SandboxJS (< 0.8.31)

## References

- [CNA](https://github.com/nyariv/SandboxJS/security/advisories/GHSA-ww7g-4gwx-m7wj)
- [CNA](https://github.com/nyariv/SandboxJS/commit/f369f8db26649f212a6a9a2e7a1624cb2f705b53)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.56%
- **EPSS Percentile:** 44.8

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._