patriksimek vm2 up to 3.11.6 Builtin Module Denylist lib/builtin.js fsp.writeFile sandbox

Summaryinfo

A vulnerability labeled as problematic has been found in patriksimek vm2 up to 3.11.6. Impacted is the function fsp.writeFile of the file lib/builtin.js of the component Builtin Module Denylist. Executing a manipulation can lead to sandbox. The identification of this vulnerability is CVE-2026-92958. The attack may be launched remotely. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability has been found in patriksimek vm2 up to 3.11.6 and classified as problematic. This vulnerability affects the function fsp.writeFile of the file lib/builtin.js of the component Builtin Module Denylist. The manipulation with an unknown input leads to a sandbox vulnerability. The CWE definition for the vulnerability is CWE-265. As an impact it is known to affect integrity, and availability. CVE summarizes:

vm2 through 3.11.6 contains a builtin-module denylist bypass in NodeVM. When the embedder uses the builtin wildcard together with negative entries (e.g. require: { builtin: ['*', '-fs', '-child_process'] }), negative entries are matched by exact module name in lib/builtin.js, so -fs removes only the builtin named fs and does not remove builtin subpaths such as fs/promises. Sandboxed code can therefore call require('fs/promises') or require('node:fs/promises') and reach the promise-based filesystem API despite fs being denied; node: prefix handling is likewise inconsistent (a -node:fs/promises entry does not block require('fs/promises')). Host file creation and writing were confirmed via fsp.writeFile(), and other fs/promises operations (cp, mkdir, rename, rm, rmdir, truncate, read operations, etc.) are also reachable. This issue is fixed in vm2 3.11.7.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-92958 since 09/17/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1611.

Upgrading to version 3.11.7 eliminates this vulnerability.

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Productinfo

Vendor

• patriksimek

Name

• vm2

Version

• 3.11.0
• 3.11.1
• 3.11.2
• 3.11.3
• 3.11.4
• 3.11.5
• 3.11.6

Website

• Product: https://github.com/patriksimek/vm2/

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