CVE-2026-25586
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.
- Score
- CVSS 3.1 10.0 Critical
- Status
- Analyzed - security-advisories@github.com
- Published
- 2026-02-06
- Last modified
- 2026-02-06
- Weaknesses
- CWE-74
Affected products
References
- https://github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3
- https://github.com/nyariv/SandboxJS/security/advisories/GHSA-jjpw-65fv-8g48
