CVE-2026-92958 patriksimek CVE debrief

Who should care

Defenders responsible for Node.js environments using vm2, especially those utilizing NodeVM in sandboxed contexts, should assess exposure and prioritize updating to version 3.11.7 or later.

Why it matters

CVE-2026-92958 is a high-severity vulnerability in vm2 that allows sandboxed code to bypass the builtin-module denylist in NodeVM. Defenders should prioritize updating to version 3.11.7 or later to prevent potential elevation of privileges and unauthorized file system operations within sandboxed environments. This issue requires verification of affected versions and prompt remediation to mitigate potential risks.

• Elevation of privileges within sandboxed environments
• Potential for unauthorized file system operations
• Bypass of security controls intended to restrict access to sensitive modules
• Need for verification of affected versions and remediation status

Technical summary

The vm2 library through version 3.11.6 contains a vulnerability in NodeVM where the builtin-module denylist can be bypassed. Specifically, when using the builtin wildcard along with negative entries, negative entries are matched by exact module name. This means that a denial of the 'fs' module does not prevent access to subpaths like 'fs/promises'. As a result, sandboxed code can still access the promise-based filesystem API by calling require('fs/promises') or require('node:fs/promises'), despite 'fs' being explicitly denied. This issue has been confirmed to allow host file creation and writing via fsp.writeFile(), and other fs/promises operations such as cp, mkdir, rename, rm, rmdir, and truncate are also accessible.

Defensive priority

Defenders should prioritize updating vm2 to version 3.11.7 or later to address the denylist bypass vulnerability.

Recommended defensive actions

• Update vm2 to version 3.11.7 or later
• Review and restrict usage of NodeVM in sandboxed environments
• Monitor for potential exploitation attempts
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description and CVSS score. Additional information is available from source references, including GitHub and Vulncheck.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.