Junglewise Threat Intelligence

CVE-2026-44007: patriksimek vm2 sandbox escape via nested NodeVM bypass

CVE-2026-44007 · Severity: critical · CVSS 9.1 · Published 2026-05-13

Executive brief

vm2 is a popular software library used to create secure 'sandboxes' for running untrusted code in Node.js environments. A vulnerability exists where an attacker can bypass these security restrictions if the sandbox is configured to allow nested virtual machines. This allows the attacker to break out of the restricted environment and execute arbitrary commands on the underlying server, potentially leading to full system takeover and data theft.

Technical details

A sandbox escape vulnerability exists in vm2's NodeVM component when the 'nesting: true' option is used. The root cause is a logic error in the legacy module resolver where the 'nesting' flag unconditionally injects the 'vm2' package into the sandbox's available modules, even if 'require: false' is explicitly set. An attacker running code within the sandbox can then 'require' the vm2 library to create a second, inner NodeVM with unrestricted permissions. This inner VM can then access sensitive Node.js built-ins like 'child_process' to execute arbitrary shell commands on the host system. The vulnerability is fixed in version 3.11.1 by preventing the combination of nesting and disabled require settings at construction time.

Affected products

  • patriksimek vm2 < 3.11.1
  • Red Hat Self-service automation portal 2 2

Timeline

  • 2026-05-01: advisory: GitHub Security Advisory published by maintainer
  • 2026-05-05: disclosed: Public disclosure on oss-security mailing list
  • 2026-05-13: patched: Fix released in version 3.11.1

References

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