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

Status: published. Published: 2026-11-04. Updated: 2026-11-04.

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`.

## Remediation

- fix: Upgrade to nvm 0.41.0 or later. (source: CNA: harborist)
- workaround: Until upgrading, check that `.nvmrc` does not start with `-` before running nvm in an untrusted project directory. (source: CNA: harborist)
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: harborist) — https://github.com/nvm-sh/nvm/commit/bce663e3873fadbe8ebbc6e07e8d76fb12d5d69e

## Affected products and versions

- nvm-sh / nvm: ≥ 0.5.0; < 0.41.0 (affected, semver). Source: CNA: harborist

## Severity and prioritization

- CVSS 4.0: 4.6 (medium); 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; source: CNA: harborist

- CVSS 3.1: 3.3 (low); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N; source: CNA: harborist

- CVSS 4.0: 4.6 (medium); 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: 7ffcee3d-2c14-4c3e-b844-86c6a321a158

- CVSS 3.1: 3.3 (low); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N; source: NVD: 7ffcee3d-2c14-4c3e-b844-86c6a321a158

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-88

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/nvm-sh/nvm/security/advisories/GHSA-xmxw-6r9w-89gc (CNA: harborist; vendor-advisory)

- https://github.com/nvm-sh/nvm/commit/bce663e3873fadbe8ebbc6e07e8d76fb12d5d69e (CNA: harborist; patch)

- https://github.com/nvm-sh/nvm/commit/bce663e3873fadbe8ebbc6e07e8d76fb12d5d69e (7ffcee3d-2c14-4c3e-b844-86c6a321a158)

- https://github.com/nvm-sh/nvm/security/advisories/GHSA-xmxw-6r9w-89gc (7ffcee3d-2c14-4c3e-b844-86c6a321a158)

## Provenance

- CNA: harborist: https://www.cve.org/CVERecord?id=CVE-2026-121749; retrieved 2026-11-04; source updated 2026-11-04

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-121749; retrieved 2026-11-05; source updated 2026-11-04

Revision: d004a282afc8092a3f018a3e62bd57fa6a6ce434edc85cb3035c013b26328d7f

Canonical: https://y2.dev/cve/CVE-2026-121749

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