CVE-2026-15921

LOWCVSS 3.1/10EPSS 0.22%

Last modified

CVE-2026-15921 is a low-severity vulnerability rated 3.1/10 on the CVSS scale. 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. EPSS estimates a 0.22% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
3.1/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N

CVSS 4.0
2.1/10

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 Probability
0.22%

13.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
nvm-shnvm>= 0.32.1, < 0.40.6

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-15921?
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.
How severe is CVE-2026-15921?
CVE-2026-15921 has a CVSS score of 3.1/10 (LOW severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.
How do I fix CVE-2026-15921?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST