Description

vm2 before 3.11.7 contains a sandbox escape vulnerability in the CLI tool that allows attackers to execute arbitrary code in the host Node.js process. Attackers can supply a malicious script file to the vm2 CLI that uses require(__filename) to re-execute itself in the host realm, bypassing sandbox isolation and accessing host modules like fs and child_process.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.6",
  "pubDate": "2026-09-17T14:18:00.637Z",
  "pubdate": "2026-09-17T14:18:00.637Z",
  "executiveSummary": "The vm2 library, specifically versions prior to 3.11.7, contains a critical sandbox escape vulnerability within its CLI interface. This flaw allows an attacker to execute arbitrary code within the host Node.js process, effectively bypassing the intended security boundaries of the sandbox.\nThe vulnerability is classified as a sandbox escape, enabling unauthorized access to host-level modules such as 'fs' (File System) and 'child_process'. By supplying a maliciously crafted script to the vm2 CLI, an attacker can transition from the restricted execution environment to the host realm.\nThis poses a severe risk to system integrity and confidentiality, as it facilitates full command execution on the host machine. Exploitation requires only the ability to provide a script file to the vm2 CLI tool. Organizations utilizing vm2 versions prior to 3.11.7 are at significant risk of system compromise and should prioritize remediation to prevent unauthorized host access.",
  "technicalDetails": "The vulnerability originates from a flaw in how the vm2 CLI utility handles input script execution. The sandbox mechanism relies on controlling the environment in which the untrusted code executes; however, the CLI implementation fails to sufficiently isolate the context when re-triggering execution cycles.\nThe core issue involves the use of 'require(__filename)' within the sandboxed script. When the CLI tool processes this instruction, the script is capable of re-executing itself within the host's Node.js runtime rather than the restricted sandbox environment. This mechanism effectively breaks the 'jail' established by the vm2 library.\nBy leveraging this re-execution, an attacker can access sensitive Node.js internals and built-in modules that are explicitly forbidden within the sandbox. Specifically, the ability to invoke 'require' for modules like 'fs' or 'child_process' grants the attacker arbitrary file system read/write capabilities and the power to spawn external processes on the underlying host operating system.\nThe attack flow follows these steps: 1) The attacker constructs a malicious payload containing the 'require(__filename)' directive designed to exploit the CLI execution path. 2) The attacker submits this script to the vm2 CLI. 3) Upon execution, the vm2 environment incorrectly resolves the file path or execution context, causing the script to be evaluated in the host realm. 4) The payload, now running with host privileges, imports administrative modules. 5) The attacker executes arbitrary commands or performs unauthorized data exfiltration.\nThis vulnerability affects vm2 versions before 3.11.7. There are no authentication requirements for this exploit, as the sandbox is intended to handle untrusted code by design. The impact is catastrophic, as the attacker achieves complete host-level command execution, allowing for full system compromise, persistence, or data theft. The vulnerability demonstrates a failure in the trust boundary between the guest script and the host Node.js environment during CLI-based invocations."
}