CVE-2025-34146

A prototype pollution vulnerability exists in @nyariv/sandboxjs versions <= 0.8.23, allowing attackers to inject arbitrary properties into Object.prototype via crafted JavaScript code. This can result in a denial-of-service (DoS) condition or, under certain conditions, escape the sandboxed environment intended to restrict code execution. The vulnerability stems from insufficient prototype access checks in the sandbox’s executor logic, particularly in the handling of JavaScript function objects returned.

CVSS 4.0

7.0CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

EPSS

0.2% chance of exploitation in the next 30 days; higher than 13% of CVEs (scores of 2026-10-25)

CWE

CWE-1321

Published

2025-07-31

Modified

2026-10-08

Record from

the NVD, synced 2026-10-19

Packages (OSV)

References

• https://gist.github.com/Hagrid29/9df27829a491080f923c4f6b8518d7e3
• https://github.com/nyariv/SandboxJS/issues/31
• https://www.npmjs.com/package/@nyariv/sandboxjs
• https://www.vulncheck.com/advisories/nyariv-sandboxjs-prototype-pollution-sandbox-escape-dos

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