CVE-2026-26954: Nyariv Sandboxjs

Critical severity, CVSS 10.0. EPSS: 0.6% chance of exploitation in the next 30 days.

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.

Affected products

• Nyariv Sandboxjs: before 0.8.34 (fixed in 0.8.34)

Published 2026-03-13. Last modified 2026-06-17.