Is CVE-2026-121746 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-121746 being exploited in the wild.

How severe is CVE-2026-121746?

Medium severity, with a CVSS score of 5.5, published 4 November 2026.

Which products and versions are affected?

Nvm-Sh Node Version Manager 0.40.0 through 0.40.8.

How is CVE-2026-121746 attacked?

It is attacked with local access.

Am I affected by CVE-2026-121746?

Check whether you run Nvm-Sh Node Version Manager at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-121746: Node Version Manager arbitrary file overwrite via symlinked .nvmrc

CVE-2026-121746 · Severity: medium · CVSS 5.5 · Published 2026-11-04

Node Version Manager (nvm) is a shell utility for managing multiple Node.js installations on a single machine. When a user runs `nvm use --save` or `nvm install --save` in a repository containing a symlinked `.nvmrc` file pointing outside the repository, the tool follows the symlink and overwrites the target file with a version string, potentially destroying critical files like shell startup scripts or SSH keys. The attacker must trick the user into cloning a malicious repository and running the save command, resulting in data loss rather than code execution.

Vendors: Nvm-Sh.

Quick answers

Is CVE-2026-121746 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-121746 being exploited in the wild.
How severe is CVE-2026-121746?: Medium severity, with a CVSS score of 5.5, published 4 November 2026.
Which products and versions are affected?: Nvm-Sh Node Version Manager 0.40.0 through 0.40.8.
Is there a fix for CVE-2026-121746?: Yes: fixed in 0.41.0. Until then: Do not use the `--save` or `-w` flags with `nvm use` and `nvm install` commands, or manually inspect `.nvmrc` files in cloned repositories to ensure they are regular files, not symlinks. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-121746 attacked?: It is attacked with local access.
Am I affected by CVE-2026-121746?: Check whether you run Nvm-Sh Node Version Manager at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 0.41.0

Do not use the `--save` or `-w` flags with `nvm use` and `nvm install` commands, or manually inspect `.nvmrc` files in cloned repositories to ensure they are regular files, not symlinks.

Technical details

The vulnerability is improper symlink resolution (CWE-59) in the `nvm_write_nvmrc` function when handling the `--save` flag with `nvm use` and `nvm install` commands. The function uses `tee` to write to `$PWD/.nvmrc` without checking if the file is a symlink, allowing it to follow symlinks and overwrite arbitrary files the user can write to. An attacker can commit a symlinked `.nvmrc` pointing to an external path (e.g., `~/.ssh/authorized_keys`), which Git recreates on clone, and when the victim runs the save commands, the target file is truncated and replaced with the resolved version string.

Affected products

nvm-sh Node Version Manager 0.40.0 through 0.40.8

Timeline

2026-11-04: disclosed

References

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