CVE-2026-121748nvm-sh nvm external control of a file name
CVE-2026-121748 is a external control of a file name in nvm-sh nvm, rated low (1.8 on CVSS 4.0).
Why this priority: Low severity, with no exploitation signal.
Published · Updated · NVD status: Awaiting Analysis
What it is
Input decides which file the software opens, so a caller can point it elsewhere.
How it is reached
An attacker can exploit it by someone who can already run code or sign in on the machine, without an account, but someone has to act first, such as opening a file or following a link. Success also depends on conditions the attacker does not fully control.
What an attacker gains
The direct impact is limited: partial access to data or a partial outage. In practice, this kind of flaw lets an attacker read or write files outside the folders the service meant to expose.
Is it being exploited?
There is no public report of exploitation yet. EPSS estimates a 0.13% chance of exploitation activity in the next 30 days, higher than 2% of scored CVEs.
What to do
- Upgrade nvm-sh nvm to 0.41.0 or later.
- Limit who can run code or sign in on the hosts that run it.
- Warn the people who use it, and filter files and links on the way in.
Description from NVD
Node Version Manager (nvm) is a POSIX-compliant shell function for managing multiple node.js versions. In versions 0.27.0 through 0.40.8, when a project's `.npmrc` sets `prefix`, `nvm use` tells the user to run `nvm use --delete-prefix`, which runs `npm config delete prefix` and `npm config delete globalconfig` in the current directory without naming a config file. npm loads the project `.npmrc` before deciding which file to edit, so that file chooses the target: `userconfig=~/.bashrc` makes npm rewrite `~/.bashrc` as ini (corrupting it), and `location=global` with `globalconfig=` leaves the chosen file at mode 0666, which on a shared machine lets another local user write to it. The attacker (the author of a cloned repository or archive, or a local user who can write a shared parent directory) chooses the file but not the bytes written, and no project code runs. Version 0.41.0 no longer lets a project `.npmrc` select which config file `--delete-prefix` edits.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- File storage the service can read or write. The flaw sits between the application and the file system it can reach.
Trust boundaries in play
- Host boundary. The attacker needs a foothold on the machine first; the flaw turns a small foothold into a bigger one.
- People who open files and links. Mail, chat and browsers are the delivery path.
- Between the application and the file system it can reach. An attacker who crosses it can read or write files outside the folders the service meant to expose.
Questions to answer about your own systems
- Where does nvm-sh nvm run in your systems, and at which version?
- Which of those hosts also run code or users you do not fully trust?
- What can it reach once compromised: which data stores, secrets and services?
Read more
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.