A vulnerability has been discovered in Node.js version 20, specifically within the experimental permission model. This flaw relates to improper handling of path traversal bypass when verifying file permissions. Please note that at the time this CVE was issued, the permission model is an experimental feature of Node.js.

Various `node:fs` functions allow specifying paths as either strings or `Uint8Array` objects. In Node.js environments, the `Buffer` class extends the `Uint8Array` class. Node.js prevents path traversal through strings (see CVE-2023-30584) and `Buffer` objects (see CVE-2023-32004), but not through non-`Buffer` `Uint8Array` objects. This is distinct from CVE-2023-32004 which only referred to `Buffer` objects. However, the vulnerability follows the same pattern using `Uint8Array` instead of `Buffer`. Please note that at the time this CVE was issued, the permission model is an experimental feature of Node.js.

A previously disclosed vulnerability (CVE-2023-30584) was patched insufficiently in commit 205f1e6. The new path traversal vulnerability arises because the implementation does not protect itself against the application overwriting built-in utility functions with user-defined implementations. Please note that at the time this CVE was issued, the permission model is an experimental feature of Node.js.