CVE-2022-39266 is a vulnerability in the isolated-vm library for Node.js, specifically affecting versions 4.3.6 and earlier. isolated-vm provides an interface to V8's Isolate, allowing sandboxed execution of JavaScript code. The vulnerability arises when untrusted V8 cached data is passed to the API via the CachedDataOptions parameter. Cached data in V8 is a mechanism intended to speed up script compilation by reusing previously compiled bytecode. However, if this cached data is crafted maliciously and accepted without proper validation, it can lead to a sandbox escape, allowing attackers to execute arbitrary code within the Node.js process hosting the isolated-vm instance. This effectively bypasses the isolation guarantees of the sandbox, compromising the integrity and confidentiality of the host environment. The root cause is improper input validation (CWE-20) and a protection mechanism failure (CWE-693), where the system fails to verify the authenticity and safety of cached data before execution. Version 4.3.7 of isolated-vm addresses this issue by updating documentation to explicitly warn developers against accepting cachedData payloads from untrusted sources, but no direct patch or code fix is provided. There are no known exploits in the wild as of the publication date, but the vulnerability presents a significant risk in environments where untrusted input might be passed to isolated-vm instances. The attack requires that the attacker can supply crafted cached data to the API, which may be feasible in multi-tenant or exposed service scenarios where user input is processed within isolated-vm sandboxes.

For European organizations, this vulnerability poses a risk primarily to applications and services that utilize the isolated-vm library for sandboxing untrusted JavaScript code. Successful exploitation could lead to arbitrary code execution within the Node.js process, potentially allowing attackers to escalate privileges, access sensitive data, or disrupt service availability. This undermines the security model of sandboxed environments, which are often used to safely run third-party or user-generated scripts. Sectors such as financial services, telecommunications, and cloud service providers in Europe that rely on Node.js microservices or serverless functions with isolated-vm could be particularly impacted. The breach of sandbox isolation can lead to data breaches, service outages, or lateral movement within internal networks. Given the medium severity and the lack of known exploits, the immediate risk is moderate, but the potential for exploitation in complex supply chains or multi-tenant cloud environments warrants attention.

1. Upgrade isolated-vm to version 4.3.7 or later, which includes updated documentation warning against accepting untrusted cachedData payloads. 2. Implement strict input validation and sanitization to ensure that any cached data passed to isolated-vm originates from trusted, verified sources only. 3. Avoid accepting cachedData from external or user-controlled inputs altogether. 4. Employ runtime monitoring and anomaly detection to identify unusual behavior in Node.js processes using isolated-vm, such as unexpected code execution or sandbox escapes. 5. Use defense-in-depth by running Node.js processes with least privilege and containerization to limit the impact of potential sandbox escapes. 6. Conduct code audits and penetration testing focusing on isolated-vm usage patterns to identify and remediate unsafe handling of cached data. 7. Maintain an inventory of applications using isolated-vm and assess exposure to untrusted input vectors. 8. Consider alternative sandboxing libraries or mechanisms if the risk cannot be adequately mitigated in legacy systems.