# CVE-2026-121748: nvm use --delete-prefix lets a project .npmrc choose which file npm rewrites or makes world-writable


- **Severity:** Low 1.8 (`CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 4 Nov 2026
- **Updated:** 9 Nov 2026
- **Also known as:** GHSA-ccgf-7gv4-xg5h

## What is CVE-2026-121748?

CVE-2026-121748 is a low-severity vulnerability in nvm-sh nvm, published on 4 Nov 2026. 

### Official description

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.

Weakness: CWE-73 (External Control of File Name or Path)

## Which versions are affected by CVE-2026-121748?


## How do I fix CVE-2026-121748?

No fix has been published for CVE-2026-121748 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-121748 being exploited?

There is no known exploitation of CVE-2026-121748 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-121748 and fix it if it is affected.

What it is: CVE-2026-121748 is a low-severity vulnerability in nvm-sh nvm, published on 4 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-121748 in the wild and no public exploit code.

Affected product: nvm-sh nvm. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-121748/ (Markdown: https://insights.sbomify.com/CVE-2026-121748/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-121748
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-121748
- OSV: https://osv.dev/vulnerability/CVE-2026-121748

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-121748/
Summaries are generated and may contain mistakes; the official description above is the record.