# CVE-2026-25586

## Summary

- **CVE ID:** CVE-2026-25586
- **Severity:** CRITICAL
- **CVSS Score:** 10 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H)
- **CWE:** CWE-74
- **Published:** Feb 6, 2026
- **Last Modified:** Mar 12, 2026

## Description

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, a sandbox escape is possible by shadowing hasOwnProperty on a sandbox object, which disables prototype whitelist enforcement in the property-access path. This permits direct access to __proto__ and other blocked prototype properties, enabling host Object.prototype pollution and persistent cross-sandbox impact. This vulnerability is fixed in 0.8.29.

## Affected Products

- nyariv — SandboxJS (< 0.8.29)

## References

- [CNA](https://github.com/nyariv/SandboxJS/security/advisories/GHSA-jjpw-65fv-8g48)
- [CNA](https://github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.65%
- **EPSS Percentile:** 48.9

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