{"id":"CVE-2026-121748","title":"nvm use --delete-prefix lets a project .npmrc choose which file npm rewrites or makes world-writable","summary":"Node Version Manager (nvm) is a POSIX-compliant shell function for managing multiple node.js versions. In versions 0.27.0 through 0.40.8, when a project's `.npmrc` sets `prefix`, `nvm use` tells the user to run `nvm use --delete-prefix`,…","severity":"low","cvss":3.6,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L","cvssSource":"cna","cwe":["CWE-73"],"vendor":"nvm-sh","product":"nvm","affected":["nvm >= 0.27.0 < 0.41.0"],"published":"2026-11-04","updated":"2026-11-04","sourceUpdated":"2026-11-04T21:29:25.656Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-121748","references":[{"url":"https://github.com/nvm-sh/nvm/security/advisories/GHSA-ccgf-7gv4-xg5h","label":"GHSA-ccgf-7gv4-xg5h"},{"url":"https://github.com/nvm-sh/nvm/commit/4049296ca8eef2067517d8cfd5ef5c0e615daa10","label":"Fix commit 4049296c"}],"tags":["cve.org"],"ingestedAt":"2026-11-05T21:36:00.616Z","slug":"CVE-2026-121748","body":"## Overview\n\nNode Version Manager (nvm) is a POSIX-compliant shell function for managing multiple node.js versions. In versions 0.27.0 through 0.40.8, when a project's `.npmrc` sets `prefix`, `nvm use` tells the user to run `nvm use --delete-prefix`, which runs `npm config delete prefix` and `npm config delete globalconfig` in the current directory without naming a config file. npm loads the project `.npmrc` before deciding which file to edit, so that file chooses the target: `userconfig=~/.bashrc` makes npm rewrite `~/.bashrc` as ini (corrupting it), and `location=global` with `globalconfig=` leaves the chosen file at mode 0666, which on a shared machine lets another local user write to it. The attacker (the author of a cloned repository or archive, or a local user who can write a shared parent directory) chooses the file but not the bytes written, and no project code runs. Version 0.41.0 no longer lets a project `.npmrc` select which config file `--delete-prefix` edits.\n\n## Affected\n\n- `nvm >= 0.27.0 < 0.41.0`\n\n## Remediation\n\nUpgrade to nvm 0.41.0 or later.\n\n### Workarounds\n\nUntil upgrading, do not run `nvm use --delete-prefix` in an untrusted project directory; remove the `prefix` setting from your own npmrc files by hand instead.","depth":"sunlit","depthScore":20,"depthScoreParts":{"impact":19.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}