CVE-2026-92956 — vm2 versions 3.10.1 through 3.11.6 contain a sandbox escape reachable from a default `new…¶

Key facts

CVE-2026-92956 is a Critical (10.0) vulnerability: vm2 versions 3.10.1 through 3.11.6 contain a sandbox escape reachable from a default `new…. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-92956
Severity	Critical (10.0)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-92956/

Details¶

English | 한국어

Description¶

vm2 versions 3.10.1 through 3.11.6 contain a sandbox escape reachable from a default new VM() sandbox when running on Node.js 26. WebAssembly.compileStreaming and WebAssembly.instantiateStreaming can produce a raw host-realm Promise that rejects with a host-realm error object; by controlling Symbol.species via Promise.prototype.finally, sandbox code receives that raw host error, walks from the host error constructor to the host Function constructor, and recovers the real host process object, gaining host Node.js capabilities (e.g. access to host modules such as fs) in the context of the process running the sandbox. No NodeVM, require permission, host object injection, or otherwise unsafe configuration is required. This is a bypass of the fix for GHSA-6j2x-vhqr-qr7q, which removed the JSPI entry points WebAssembly.promising and WebAssembly.Suspending. The issue is fixed in 3.11.7.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-92956
CVSS Score	10.0

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-92956/poc.py

Usage¶

# Run PoC against target
python3 poc.py --target <TARGET_URL>

# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>

⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.

Test Lab¶

This repository includes a Docker-based test environment with both vulnerable and patched applications.

Quick Start¶

# Clone and navigate to CVE directory
cd CVE-2026-92956

# Start both applications
docker-compose up -d

# Run tests
./run-tests.sh    # Linux/Mac
./run-tests.ps1   # Windows PowerShell

Application Endpoints¶

Application	URL	Status
Vulnerable App	http://localhost:8080	Shows vulnerability
Patched App	http://localhost:8081	Demonstrates fix

Directory Structure¶

├── README.md           # English documentation
├── README_KO.md        # Korean documentation
├── poc.py              # PoC detection script
├── docker-compose.yml  # Container orchestration
├── run-tests.sh        # Linux/Mac test runner
├── run-tests.ps1       # Windows test runner
├── vulnerable-app/     # Vulnerable version
│   ├── app.py
│   ├── Dockerfile
│   └── requirements.txt
└── patched-app/        # Fixed version
    ├── app.py
    ├── Dockerfile
    └── requirements.txt

References¶

https://github.com/patriksimek/vm2/security/advisories/GHSA-wjwh-qqvp-g4p4
https://www.vulncheck.com/advisories/vm2-3.10.1-through-3.11.6-sandbox-escape-via-webassembly-compilestreaming

Generated by PoC Generator on 2026-09-18T00:23:33.085512228

Frequently asked questions¶

What is CVE-2026-92956?¶

CVE-2026-92956 is a Critical (10.0) vulnerability: vm2 versions 3.10.1 through 3.11.6 contain a sandbox escape reachable from a default `new…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-92956?¶

Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.

How do I block or mitigate CVE-2026-92956?¶

Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.

For authorized security testing and research only. See the full source and NVD record.