Vulnerability Description
Node Version Manager (nvm) is a POSIX-compliant shell function for managing multiple node.js versions. In versions 0.32.1 through 0.40.5, `nvm ls-remote` (and other commands that refresh remote LTS aliases, such as `nvm install --lts`) parse the node.js mirror's `index.tab` and use each release's LTS codename field as an alias filename without validating it. A malicious, compromised, or man-in-the-middled mirror can return an LTS codename containing path-traversal sequences such as `../../../.bashrc`, causing nvm to write the associated version string to a path outside `$NVM_DIR/alias`. With the default layout (`$NVM_DIR` is `~/.nvm`), this can create or overwrite files in the user's home directory, including shell startup files, which can lead to code execution in a later shell session. Exploitation requires the victim to use a hostile mirror -- via a compromised mirror or CDN, a network man-in-the-middle, or a maliciously configured `NVM_NODEJS_ORG_MIRROR`/`NVM_IOJS_ORG_MIRROR` -- and to run an affected command. Version 0.40.6 validates remote LTS codenames as safe alias filenames and rejects `..` path components when writing alias files.
CVSS Score
LOW
Related Weaknesses (CWE)
References
- https://github.com/nvm-sh/nvm/commit/9275c5badda1d9d0cdad6f34598a111033eadb42
- https://github.com/nvm-sh/nvm/security/advisories/GHSA-4ghp-wxpw-rhpg
- https://github.com/nvm-sh/nvm/security/advisories/GHSA-4ghp-wxpw-rhpg
FAQ
What is CVE-2026-15921?
CVE-2026-15921 is a vulnerability with a CVSS score of 3.1 (LOW). Node Version Manager (nvm) is a POSIX-compliant shell function for managing multiple node.js versions. In versions 0.32.1 through 0.40.5, `nvm ls-remote` (and other commands that refresh remote LTS al...
How severe is CVE-2026-15921?
CVE-2026-15921 has been rated LOW with a CVSS base score of 3.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-15921?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.