8.6
HIGH CVSS 3.1
CVE-2026-47209
vm2: Bridge Proxy set trap ignores receiver parameter, enabling host object property injection via prototype chain
Description

vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, the BaseHandler.set trap in bridge.js (line 1231) ignores the receiver parameter and unconditionally writes to the host target object. Per the Proxy set trap specification, when receiver !== proxy (e.g., when a child object inherits from the proxy via Object.create), the property assignment should create an own property on the receiver, not on the proxy target. The current implementation always calls otherReflectSet(object, key, value) against the host target, causing all inherited property writes to leak through to the host object. This bug provides an alternative attack vector for writing dangerous cross-realm Symbol keys (e.g., nodejs.util.promisify.custom) to host objects, bypassing any future per-trap isDangerousCrossRealmSymbol guard on the direct set path. This issue has been patched in version 3.11.4.

INFO

Published Date :

June 12, 2026, 3:16 p.m.

Last Modified :

June 12, 2026, 3:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-47209 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH [email protected]
Solution
Update vm2 to version 3.11.4 or later to address the BaseHandler.set trap vulnerability.
  • Update vm2 to version 3.11.4 or later.
  • Apply patches provided by the vendor.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-47209.

URL Resource
https://github.com/patriksimek/vm2/commit/26d0318b5e6555be4b187ba05d6cf378ccecfe22
https://github.com/patriksimek/vm2/releases/tag/v3.11.4
https://github.com/patriksimek/vm2/security/advisories/GHSA-c4cf-2hgv-2qv6
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-47209 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-47209 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-47209 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-47209 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jun. 12, 2026

    Action Type Old Value New Value
    Added Description vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, the BaseHandler.set trap in bridge.js (line 1231) ignores the receiver parameter and unconditionally writes to the host target object. Per the Proxy set trap specification, when receiver !== proxy (e.g., when a child object inherits from the proxy via Object.create), the property assignment should create an own property on the receiver, not on the proxy target. The current implementation always calls otherReflectSet(object, key, value) against the host target, causing all inherited property writes to leak through to the host object. This bug provides an alternative attack vector for writing dangerous cross-realm Symbol keys (e.g., nodejs.util.promisify.custom) to host objects, bypassing any future per-trap isDangerousCrossRealmSymbol guard on the direct set path. This issue has been patched in version 3.11.4.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
    Added CWE CWE-693
    Added Reference https://github.com/patriksimek/vm2/commit/26d0318b5e6555be4b187ba05d6cf378ccecfe22
    Added Reference https://github.com/patriksimek/vm2/releases/tag/v3.11.4
    Added Reference https://github.com/patriksimek/vm2/security/advisories/GHSA-c4cf-2hgv-2qv6
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.