Promise Callback Sanitization Bypass in vm2 Enables Sandbox Escape

Publication date: 2026-01-26

Last updated on: 2026-02-17

Assigner: GitHub, Inc.

Description

vm2 is an open source vm/sandbox for Node.js. In vm2 prior to version 3.10.2, `Promise.prototype.then` `Promise.prototype.catch` callback sanitization can be bypassed. This allows attackers to escape the sandbox and run arbitrary code. In lib/setup-sandbox.js, the callback function of `localPromise.prototype.then` is sanitized, but `globalPromise.prototype.then` is not sanitized. The return value of async functions is `globalPromise` object. Version 3.10.2 fixes the issue.

CVSS Scores

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Meta Information

Published

2026-01-26

Last Modified

2026-02-17

Generated

2026-07-06

AI Q&A

2026-01-27

EPSS Evaluated

2026-07-05

NVD

CVE-2026-22709

Affected Vendors & Products

Vendor	Product	Version / Range
vm2_project	vm2	to 3.10.2 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-913	The product does not properly restrict reading from or writing to dynamically-managed code resources such as variables, objects, classes, attributes, functions, or executable instructions or statements.
CWE-94	The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
CWE-693	The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product.

Attack-Flow Graph

Executive Summary

This vulnerability in vm2 prior to version 3.10.2 involves a bypass of the sanitization of Promise callback functions. Specifically, while the callback function of localPromise.prototype.then is sanitized, the globalPromise.prototype.then is not. Since async functions return a globalPromise object, attackers can exploit this to escape the sandbox and execute arbitrary code.

Impact Analysis

An attacker exploiting this vulnerability can escape the vm2 sandbox and run arbitrary code on the host system. This can lead to full compromise of the environment where vm2 is used, potentially allowing unauthorized access, data manipulation, or disruption of services.

Mitigation Strategies

Upgrade vm2 to version 3.10.2 or later, as this version fixes the Promise callback sanitization bypass issue that allows sandbox escape and arbitrary code execution.

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