CVE-2026-44004: vm2 Sandbox Vulnerability Leads to Host Memory Exhaustion
The National Vulnerability Database has detailed CVE-2026-44004, a critical vulnerability in vm2, an open-source Node.js sandboxing library. Prior to version 3.11.0, sandboxed code can exploit Buffer.alloc() to allocate an arbitrary amount of memory directly on the host heap. This is not a theoretical issue; Buffer.alloc is a synchronous C++ native call, meaning vm2’s timeout mechanisms are powerless to interrupt it.
This flaw allows a single malicious request to exhaust the host’s memory, triggering a FATAL ERROR: Reached heap limit and crashing the entire process. The National Vulnerability Database assigns this a CVSS score of 7.5 (HIGH), underscoring the severe availability impact. This is a denial-of-service vector that any attacker with code execution within the sandbox can leverage to bring down a Node.js application.
Defenders must understand the attacker’s calculus here: this is a low-effort, high-impact attack. It doesn’t require complex exploitation; simply calling a function with a large size is enough. CISOs need to ensure their development teams are aware of this specific vulnerability and prioritize patching vm2 to version 3.11.0 or later. Ignoring this is leaving a clear path for attackers to disrupt service availability.
What This Means For You
- If your Node.js applications use vm2 for sandboxing, verify immediately that you are running version 3.11.0 or newer. Older versions are vulnerable to CVE-2026-44004, allowing a sandbox escape to trigger a denial-of-service on the host. Patching is the only mitigation.
Related ATT&CK Techniques
🛡️ Detection Rules
3 rules · 6 SIEM formats3 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.
CVE-2026-44004: vm2 Buffer.alloc Heap Exhaustion Attempt
title: CVE-2026-44004: vm2 Buffer.alloc Heap Exhaustion Attempt
id: scw-2026-05-13-ai-1
status: experimental
level: critical
description: |
Detects attempts to exploit CVE-2026-44004 by monitoring Node.js processes (node.exe) executing commands that include 'Buffer.alloc'. This specific call, when used with an arbitrary large size within a vulnerable vm2 version (prior to 3.11.0), can lead to host memory exhaustion. This rule aims to catch the direct exploitation attempt.
author: SCW Feed Engine (AI-generated)
date: 2026-05-13
references:
- https://shimiscyberworld.com/posts/nvd-CVE-2026-44004/
tags:
- attack.defense_evasion
- attack.t1499
logsource:
category: process_creation
detection:
selection:
Image|contains:
- 'node.exe'
CommandLine|contains:
- 'Buffer.alloc'
condition: selection
falsepositives:
- Legitimate administrative activity
Source: Shimi's Cyber World · License & reuse
Indicators of Compromise
| ID | Type | Indicator |
|---|---|---|
| CVE-2026-44004 | DoS | vm2 < 3.11.0 |
| CVE-2026-44004 | DoS | Node.js vm/sandbox |
| CVE-2026-44004 | DoS | Buffer.alloc() with arbitrary size in sandboxed code |
| CVE-2026-44004 | DoS | Host memory exhaustion leading to process crash |
Written by SCW Vulnerability Desk
Source & Attribution
| Source Platform | NVD |
| Channel | National Vulnerability Database |
| Published | May 13, 2026 at 21:16 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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