# CVE-2026-121749: nvm passes the version pattern to grep without -e, letting a .nvmrc inject grep options and read local files


- **Severity:** Medium 4.6 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/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-xmxw-6r9w-89gc

## What is CVE-2026-121749?

CVE-2026-121749 is a medium-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 0.5.0 through 0.40.8, the requested version pattern is passed to `grep` as a bare argument, without `-e`, in `nvm_ls_remote_index_tab`, `nvm_remote_version`, and `nvm_ls_cached`. A `.nvmrc` whose first line starts with `-`, such as `-Rohenpm_[A-Za-z0-9]*`, is parsed as grep options; with GNU grep, `-R` searches the current directory recursively (following symlinks) instead of the version list. On a bare `nvm install`, nvm then treats a matched string from those files as the version, prints it, and requests it from the configured mirror inside download URLs, so for example a repository containing a symlink to `../../.npmrc` can leak the user's npm token to the terminal and to the mirror's and any proxy's logs. The disclosure is read-only and limited to the characters `0-9A-Za-z._+-`. Version 0.41.0 passes every version pattern to grep with `-e`.

Weakness: CWE-88 (Improper Neutralization of Argument Delimiters in a Command)

## Which versions are affected by CVE-2026-121749?


## How do I fix CVE-2026-121749?

No fix has been published for CVE-2026-121749 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-121749 being exploited?

There is no known exploitation of CVE-2026-121749 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-121749 and fix it if it is affected.

What it is: CVE-2026-121749 is a medium-severity vulnerability in nvm-sh nvm, published on 4 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-121749 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-2026-121749/ (Markdown: https://insights.sbomify.com/CVE-2026-121749/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-121749
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-121749
- OSV: https://osv.dev/vulnerability/CVE-2026-121749

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-121749/
Summaries are generated and may contain mistakes; the official description above is the record.