CVE-2026-47131
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedvm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, by combining Buffer.call.call({}.__lookupGetter__, Buffer, "__proto__"), Buffer.call.call({}.__lookupSetter__, Buffer, "__proto__"), and Node.js's ERR_INVALID_ARG_TYPE Error, the host's TypeError constructor can be obtained, which allows the escape from the sandbox. This allows attackers to run arbitrary code. This issue has been patched in version 3.11.4.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidencevm2 versions prior to 3.11.4 contain a sandbox escape vulnerability allowing arbitrary code execution. The attack chains Buffer.call.call() with __lookupGetter__/__lookupSetter__ and Node.js ERR_INVALID_ARG_TYPE Error to leak the host's TypeError constructor, enabling complete sandbox escape.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check if vm2 is installed as a dependencyRun 'npm list vm2' in your project directory, or inspect package.json and package-lock.json for the vm2 entryAffected if vm2 appears in your dependencies
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Identify the installed vm2 versionRun 'npm list vm2' or check the version field in node_modules/vm2/package.jsonAffected if The version is lower than 3.11.4 (e.g., 3.11.3, 3.10.x, etc.)
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Determine if vm2 is used to execute untrusted codeSearch your codebase for vm2 usage patterns such as 'new vm.Script()', 'vm.runInNewContext()', or 'vm.runInThisContext()' with user-controlled inputAffected if Your application passes untrusted or external input directly to vm2 sandbox methods without additional security layers
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Check for sandbox configuration exposureReview code where the vm2 sandbox is created; look for whether the sandboxed code can access Buffer, process, or other Node.js built-insAffected if The sandbox allows access to Buffer or permits prototype chain access that could enable the Buffer.call.call() attack vector
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Inspect error handling pathsSearch for error-throwing code within vm2 contexts, particularly where TypeError or ERR_INVALID_ARG_TYPE errors may be generated and caughtAffected if Your vm2 usage involves catching or triggering Node.js errors within the sandbox that could leak the TypeError constructor
You are affected if vm2 version is below 3.11.4 AND your application uses vm2 to execute untrusted code without additional hardening layers.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade vm2 to version 3.11.4 or later. If upgrading is not feasible, avoid using vm2 to run untrusted code.
vm2 version 3.11.4
- 1. Check current vm2 version by running `npm list vm2` in your project directory
- 2. Update vm2 to version 3.11.4 or later by running `npm install [email protected]` or `npm install vm2@latest`
- 3. Verify the installation was successful by running `npm list vm2`
- 4. Test your application's sandbox functionality to ensure the upgrade does not break expected behavior
- 5. Rebuild any lockfiles if necessary (run `npm install` to regenerate package-lock.json)
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,376.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-47131 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-47131 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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