CVE-2026-25520

SandboxJS has a Sandbox Escape

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, The return values of functions aren't wrapped. Object.values/Object.entries can be used to get an Array containing the host's Function constructor, by using Array.prototype.at you can obtain the hosts Function constructor, which can be used to execute arbitrary code outside of the sandbox. This vulnerability is fixed in 0.8.29.

Affected

nyariv · SandboxJS

CVSS v3.1 GITHUB

10.0 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS

0.89% chance of exploitation in the next 30 days, 59th percentile

Published

2026-02-06

Proof-of-concept exploits (1)

• advisories/GHSA-58jh-xv4v-pcx4

Security advisories

• nyariv/SandboxJS/security/advisories/GHSA-58jh-xv4v-pcx4
• nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3

References

• CVE Record
• NVD entry