CVE-2026-92947

vm2 before 3.11.7 exposes Node's shared Buffer pool to sandboxed code, allowing disclosure of host memory used by Buffer.from, Buffer.concat, and related allocations. Sandboxed code can read and write to host-realm buffers by acquiring ArrayBuffers from small allocations, leading to sensitive data exposure and potential denial-of-service.

vm2 before 3.11.7 exposes Node's shared Buffer pool to sandboxed code, allowing disclosure of host memory used by Buffer.from, Buffer.concat, and related allocations. Sandboxed code can read and write to host-realm buffers by acquiring ArrayBuffers from small allocations, leading to sensitive data exposure and potential denial-of-service.

Summary

Sandboxed code is able to disclose host memory used by small allocations by Buffer.from, Buffer.concat.

Details

vm2 exposes Buffer object to sandboxed code by default. Small Buffer allocations (for example, Buffer.allocUnsafe(), Buffer.from(array), Buffer.from(string), and Buffer.concat()) use the same Buffer pool, which is shared with the sandbox. This allows sandboxed code to disclose host memory used by the functions listed above.

PoC

Tested against [email protected] in the node REPL.

Buffer.from('host-memory-should-not-leak-to-sandbox')
new (require('vm2').VM)().run(`Buffer.from(Buffer.from([0]).buffer, 0, Buffer.from([0]).buffer.byteLength).toString('ascii')`)

<img width="1044" height="104" alt="Screenshot 2026-07-23 at 17 54 15" src="https://github.com/user-attachments/assets/987b860c-6702-4818-bfaa-c77919c777e5" />

Impact

Since sandbox acquires an ArrayBuffer that is used by the host, it can disclose sensitive data going through functions mentioned above and even write to these buffers, which can lead to sensitive data exposure and potentially denial-of-service.

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-fcqc-726x-5wfc This link is maintained to preserve external references.

Original Description

vm2 before 3.11.7 exposes Node's shared Buffer pool to sandboxed code, allowing disclosure of host memory used by Buffer.from, Buffer.concat, and related allocations. Sandboxed code can read and write to host-realm buffers by acquiring ArrayBuffers from small allocations, leading to sensitive data exposure and potential denial-of-service.

vm2 before 3.11.7 exposes Node's shared Buffer pool to sandboxed code, allowing disclosure of host memory used by Buffer.from, Buffer.concat, and related allocations. Sandboxed code can read and write to host-realm buffers by acquiring ArrayBuffers from small allocations, leading to sensitive data exposure and potential denial-of-service.

vm2 before 3.11.7 exposes Node's shared Buffer pool to sandboxed code, allowing disclosure of host memory used by Buffer.from, Buffer.concat, and related allocations. Sandboxed code can read and write to host-realm buffers by acquiring ArrayBuffers from small allocations, leading to sensitive data exposure and potential denial-of-service.