CVE-2025-34146 nyariv sandboxjs 0.8.23 Prototype Pollution Sandbox Escape DoS
Attackers can escape the sandbox and execute arbitrary code or cause denial of service via prototype pollution in the sandboxjs library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-34146?
CVE-2025-34146 is a high-severity code injection vulnerability in nyariv sandboxjs, published on 31 Jul 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-1321
Which versions are affected by CVE-2025-34146?
2 open source packages ship an affected version, including @nyariv/sandboxjs.
| Package | Affected | Fixed in |
|---|---|---|
@nyariv/sandboxjs npm | All versions | 0.8.24 |
@nyariv/sandboxjs npm | All versions | 0.8.24 |
How do I fix CVE-2025-34146?
Upgrade @nyariv/sandboxjs to 0.8.24 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2025-34146 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-34146 exists.
Sources
Also known as GHSA-9qm3-6qrr-c76m.