The vm2 Node.js sandbox versions >=3.9.6 and <3.11.0 contain a prototype pollution vulnerability (CWE-1321) due to exposing mutable proxies for host intrinsic prototypes. Sandbox code can modify shared host Object.prototype, Array.prototype, and Function.prototype via otherReflectSet() and otherReflectDefineProperty() calls, enabling modification of host environment prototypes from inside the sandbox. This vulnerability is addressed in vm2 version 3.11.0. The CVSS 3.1 base score is 10.0 (critical) with network attack vector, no privileges required, no user interaction, scope changed, no confidentiality impact, high integrity and availability impact. The vendor advisory from Red Hat confirms the issue but does not explicitly state patch availability beyond the fixed version 3.11.0.

An attacker with the ability to run JavaScript inside the vm2 sandbox can modify fundamental JavaScript prototypes in the host environment, potentially leading to severe integrity and availability impacts. This can compromise the isolation guarantees of the sandbox, allowing malicious code to affect the host application or environment. The CVSS score of 10.0 reflects the critical nature of this vulnerability with high impact on integrity and availability and no required privileges or user interaction.

A fix is available in vm2 version 3.11.0. Users should upgrade to version 3.11.0 or later to remediate this vulnerability. The Red Hat advisory confirms the vulnerability but does not provide additional mitigation steps beyond upgrading. Patch status is confirmed by the fixed version 3.11.0. No other mitigations are indicated by the vendor advisory.