VulnerabilityAnalyzed

CVE-2026-25520

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.

CRITICAL 10.0EPSS 0.80%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.80%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1: 10.0 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS: 0.80% probability · 54th percentile
CISA KEV: Not listed
Weakness: CWE-74
Affected: nyariv/sandboxjs
Source: security-advisories@github.com

References

https://github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3Patch
https://github.com/nyariv/SandboxJS/security/advisories/GHSA-58jh-xv4v-pcx4Exploit, Vendor Advisory
https://github.com/nyariv/SandboxJS/security/advisories/GHSA-58jh-xv4v-pcx4Exploit, Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.