vm2 Sandbox Escape Vulnerability (CVE-2026-26956) Allows Critical Code Execution

May 04, 2026 20:16 /CRITICAL /CVSS 9.8/10

Written by SCW Vulnerability Desk Vulnerability Intelligence

SCW vulnerabilitycvecriticalhigh-severitycode-executioncwe-693

vm2 Sandbox Escape Vulnerability (CVE-2026-26956) Allows Critical Code Execution

The National Vulnerability Database (NVD) has detailed a critical sandbox escape vulnerability, CVE-2026-26956, affecting the vm2 Node.js sandboxing library. In versions prior to 3.10.5, attackers could execute arbitrary code on the host system by exploiting the VM.run() function. This allows malicious code within the sandbox to gain access to and control host processes, bypassing intended security boundaries entirely.

The National Vulnerability Database highlights the severity of this flaw with a CVSS score of 9.8 (CRITICAL). The attack vector is network-accessible, requires no privileges or user interaction, and results in complete confidentiality, integrity, and availability compromise. This means an attacker can compromise systems remotely without any user assistance, making it a prime target for widespread exploitation.

Given the critical nature and ease of exploitation, organizations leveraging vm2 for sandboxing untrusted code must immediately update to version 3.10.5 or later. Failure to patch exposes systems to severe remote code execution risks, potentially leading to full system compromise. Defenders should also review any instances where vm2 is deployed to assess their current exposure.

What This Means For You

If your development or security operations use vm2 for sandboxing Node.js code, immediately verify you are running version 3.10.5 or higher. This vulnerability allows for full sandbox escape and arbitrary code execution on the host, a critical risk that demands urgent patching.

Related ATT&CK Techniques

T1059.003 Command and Scripting Interpreter: Windows Command Shell Execution T1204.002 Malicious File: Exploitation for Privilege Escalation Privilege Escalation T1574.002 Hijack Execution Flow: DLL Side-Loading Privilege Escalation

🛡️ Detection Rules

3 rules · 6 SIEM formats

3 detection rules auto-generated for this incident, mapped to MITRE ATT&CK. Sigma YAML is free — export to any SIEM format via the Intel Bot.

critical T1059.003 Execution

vm2 Sandbox Escape to Host Command Execution - CVE-2026-26956

Sigma YAML — free preview

title: vm2 Sandbox Escape to Host Command Execution - CVE-2026-26956
id: scw-2026-05-04-ai-1
status: experimental
level: critical
description: |
  Detects the vm2 sandbox escape vulnerability (CVE-2026-26956) where an attacker within a vm2 sandbox (running via node.exe) attempts to execute arbitrary host commands using Node.js's child_process module. This rule specifically looks for the pattern of vm2's `runInNewContext` being used in conjunction with direct calls to `child_process` methods, indicating an attempt to break out of the sandbox.
author: SCW Feed Engine (AI-generated)
date: 2026-05-04
references:
  - https://shimiscyberworld.com/posts/nvd-CVE-2026-26956/
tags:
  - attack.execution
  - attack.t1059.003
logsource:
    category: process_creation
detection:
  selection:
      ParentImage|contains:
          - 'node.exe'
      Image|contains:
          - 'node.exe'
      CommandLine|contains:
          - 'require(\'vm\').runInNewContext'
      CommandLine|contains:
          - 'process.mainModule.require(\'child_process\').exec'
      CommandLine|contains:
          - 'process.mainModule.require(\'child_process\').spawn'
      CommandLine|contains:
          - 'process.mainModule.require(\'child_process\').execFile'
      CommandLine|contains:
          - 'process.mainModule.require(\'child_process\').execSync'
      CommandLine|contains:
          - 'process.mainModule.require(\'child_process\').spawnSync'
  condition: selection
falsepositives:
  - Legitimate administrative activity

Source: Shimi's Cyber World · License & reuse

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Indicators of Compromise

ID	Type	Indicator
CVE-2026-26956	RCE	vm2 library versions <= 3.10.4
CVE-2026-26956	Sandbox Escape	vm2 library versions <= 3.10.4
CVE-2026-26956	Code Injection	vm2 library versions <= 3.10.4, specifically within VM.run() context

Written by SCW Vulnerability Desk

Source & Attribution

Source Platform	NVD
Channel	National Vulnerability Database
Published	May 04, 2026 at 20:16 UTC

This content was AI-rewritten and enriched by Shimi's Cyber World based on the original source. All intellectual property rights remain with the original author.

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What This Means For You

Related ATT&CK Techniques

🛡️ Detection Rules

vm2 Sandbox Escape to Host Command Execution - CVE-2026-26956

Indicators of Compromise

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