nvm path traversal via a malicious mirror's LTS codename writes outside the alias directory
Summary
| CVE | CVE-2026-15921 |
|---|---|
| State | PUBLISHED |
| Assigner | harborist |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-15 22:16:45 UTC |
| Updated | 2026-07-16 14:16:49 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 2.1 LOW from 7ffcee3d-2c14-4c3e-b844-86c6a321a158
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:L/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
EPSS: 0.002250000 probability, percentile 0.131980000 (date 2026-07-20)
Problem Types: CWE-22 | CWE-73 | CWE-22 CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') | CWE-73 CWE-73 External Control of File Name or Path
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 7ffcee3d-2c14-4c3e-b844-86c6a321a158 | Secondary | 2.1 | LOW | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 2.1 | LOW | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N |
| 3.1 | 7ffcee3d-2c14-4c3e-b844-86c6a321a158 | Secondary | 3.1 | LOW | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N |
| 3.1 | CNA | CVSS | 3.1 | LOW | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:L/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
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/nvm-sh/nvm/security/advisories/GHSA-4ghp-wxpw-rhpg | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | |
| github.com/nvm-sh/nvm/commit/9275c5badda1d9d0cdad6f34598a111033eadb42 | 7ffcee3d-2c14-4c3e-b844-86c6a321a158 | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Sy2n0 (https://github.com/Sy2n0) (en)
CNA: Jordan Harband (https://github.com/ljharb) (en)
Additional Advisory Data
Solutions
CNA: Upgrade to nvm 0.40.6 or later, which validates remote LTS codenames and rejects `..` path components when writing alias files. (Only needed if using a non-default mirror whose metadata contents you do not trust).
Workarounds
CNA: Until upgrading, only run `nvm ls-remote` and LTS-refreshing commands against trusted mirrors over TLS, and ensure `NVM_NODEJS_ORG_MIRROR` and `NVM_IOJS_ORG_MIRROR` point only at trusted endpoints.