Attack Chain

1. The attacker provides malicious JavaScript code to the vm2 sandbox.
2. The malicious code defines an async generator function that utilizes the yield* expression.
3. The code triggers a host exception within the sandbox environment.
4. The exception is caught within the async generator using a specially crafted iterator.
5. The attacker manipulates the caught exception object to access host objects and functions.
6. This access is used to bypass the sandbox restrictions.
7. The attacker gains access to the child_process module.
8. The attacker executes arbitrary commands on the host system using child_process.execSync().

Impact

Successful exploitation of this vulnerability allows attackers to perform Remote Code Execution (RCE) on the host system. This can lead to a complete compromise of the affected system, including data theft, system corruption, and further propagation of malicious activity. Given the popularity of vm2 in sandboxing untrusted JavaScript code, a wide range of applications and systems could be at risk if they are using versions 3.11.2 or earlier.

Recommendation

• Upgrade to vm2 version 3.11.3 or later to patch CVE-2026-45411.
• Deploy the Sigma rule “Detect VM2 Sandbox Breakout via Async Generator” to your SIEM to detect potential exploitation attempts.
• Implement strict input validation and sanitization to minimize the risk of malicious code being introduced into the vm2 sandbox.