CVE-2026-47140: vm2: NodeVM builtin denylist bypass via process and inspector/promises allows host code execution

Synopsis

A sandbox escape vulnerability exists in vm2, a widely used Node.js sandboxing library. The NodeVM builtin denylist fails to block access to the process object and the inspector/promises module, both of which provide direct paths to host-side execution primitives. An unauthenticated attacker who can submit code to the sandbox can escape the sandbox entirely and execute arbitrary code in the host Node.js process. A patched-image rebuild at version 3.11.4 is available on HarborGuard for affected environments.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The vulnerable service must be reachable over the network; any attacker who can send code or input to the vm2 sandbox endpoint can trigger the bypass.

• AuthenticationNot required

  No credentials or account are needed; the exploit path is open to any party that can reach the sandbox interface.

• Victim interactionNot required

  No user action is required; the attacker submits malicious code directly to the sandbox and exploitation proceeds without any victim involvement.

• Attack complexityDetail

  The exploit is reliable and condition-free; no race conditions, memory layout knowledge, or environmental prerequisites are required to escape the sandbox.

Blast Radius

• Attacker executes arbitrary code inside the host Node.js process, inheriting all OS-level permissions that process holds.
• Attacker reads any data accessible to the host process, including environment variables, secrets, and files on the container filesystem.
• Attacker writes or deletes files, modifies application state, or injects malicious logic into the running process.
• Attacker can crash or destabilize the host process, taking down the service entirely.