CVE-2026-121747
nvm prints the contents of any readable file through a symlinked .nvmrc
Node Version Manager (nvm) is a POSIX-compliant shell function for managing multiple node.js versions. In versions 0.2.0 through 0.40.8, nvm does not check whether `.nvmrc` is a symbolic link. A repository or archive that ships `.nvmrc` as a symlink to another file (for example `../../.npmrc`, or `/proc/self/environ` on Linux) makes a plain `nvm use`, `nvm install`, `nvm which`, `nvm exec`, `nvm run`, or `nvm-exec` read that file and print its contents in the invalid-`.nvmrc` message (even with `--silent`) or, for a one-line file, in the `Found ... with version <...>` message; with the README's zsh `load-nvmrc` or bash `cdnvm` hook installed, entering the directory is enough. nvm sends the content nowhere; the attacker learns it only where they can see the victim's output, such as a CI log for a contributed branch. Version 0.41.0 still follows a symlinked `.nvmrc`, so deliberate links to another version file keep working, but never prints its content, and accepts it only if it contains a version or the name of an existing alias; the README's bash `cdnvm` hook, which read `.nvmrc` itself, now gets the version from nvm, so users of that hook must also update their copy of it.
Fixes and workarounds
Fix
Upgrade to nvm 0.41.0 or later.
Source: CNA: harboristWorkaround
Until upgrading, check for a symlinked `.nvmrc` (`ls -l .nvmrc`) before running nvm in an untrusted project directory, and do not run nvm in CI for untrusted branches where its output is visible to their authors.
Source: CNA: harboristFix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: harboristFix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: harboristAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| nvm nvm-sh |
≥ 0.2.0; < 0.41.0 (affected, semver)
Other versions: unaffected |
CNA: harborist |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 6.7 medium |
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N | CNA: harborist |
| 3.1 / 5.5 medium |
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N | CNA: harborist |
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-j6ch-mq5c-3h4xCNA: harborist · vendor-advisory
- https://github.com/nvm-sh/nvm/commit/67268ebcb6e1a26ae3d71b3710d6333bb7358662CNA: harborist · patch
- https://github.com/nvm-sh/nvm/commit/c314f1cbb3c301c587a4e4f96511d31f1134ffd1CNA: harborist · patch
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