CVE-2026-123829 Node.js is vulnerable to Permission Model file-name disclosure via recursive fs.watch
Code running under Node.js Permission Model can learn names of files it is denied to read via recursive fs.watch on macOS or Windows.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Harmful if only installed
- No
- Needs a specific call
- Yes
- Fix
- Available
What is CVE-2026-123829?
CVE-2026-123829 is a low-severity information disclosure vulnerability in nodejs node, published on 11 Nov 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A Permission Model bypass in Node.js recursive file watching discloses the names of files and directories the process is not permitted to read. On macOS and Windows, fs.watch() and fs.promises.watch() in recursive mode are backed by the native libuv watcher: FSEventWrap::Start checks kFileSystemRead only once, on the watched root, and FSEventWrap::OnEvent then forwards every filename libuv reports (relative paths at any depth) to the JavaScript callback without checking that each path is covered by the read grant. Code running under --permission with an exact read grant on a directory can therefore learn names such as sub/secret.txt even though readdir on that subdirectory is denied. The flaw exposes names and timing metadata, not file contents, and requires macOS or Windows plus files created under the watched directory by another actor. This vulnerability affects Node.js 26.x, 24.x, and 22.x.
Weakness: CWE-200
Which versions are affected by CVE-2026-123829?
An affected version is only exploitable if your software calls fs.watch() or fs.promises.watch(). Many projects that include it are not exposed.
How do I fix CVE-2026-123829?
No fix published yet.
Upgrade, and rotate any secrets that may have been exposed. More about Information disclosure.
Is CVE-2026-123829 being exploited?
There is no known exploitation of CVE-2026-123829 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-123829, BELL-CVE-2026-123829, DEBIAN-CVE-2026-123829, GHSA-fxj5-xgw6-cx7g, UBUNTU-CVE-2026-123829.