CVE-2025-34146
CVE-2025-34146 is a high-severity vulnerability with a CVSS 4.0 base score of 7.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1321.
Key facts
- Severity: High (CVSS 4.0 base score 7.0)
- EPSS exploit prediction: 0% (10th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2025-23278
- Weakness: CWE-1321
- Published:
- Last modified:
Description
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.
Frequently asked questions
- What is 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.
- How severe is CVE-2025-34146?
- CVE-2025-34146 has a CVSS 4.0 base score of 7.0, rated high severity.
- Is CVE-2025-34146 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2025-34146?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2025-34146 have an EU (EUVD) identifier?
- Yes. CVE-2025-34146 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-23278.
- When was CVE-2025-34146 published?
- CVE-2025-34146 was published on 2025-07-31 and last updated on 2026-06-17.
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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