CVE-2026-25586
Severity CVSS v4.0:
Pending analysis
Type:
CWE-74
Injection
Publication date:
06/02/2026
Last modified:
06/02/2026
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.
Impact
Base Score 3.x
10.00
Severity 3.x
CRITICAL



