The vulnerability allows an attacker to write or delete arbitrary files during pnpm install, leading to potential compromise of the entire project repository. It manifests through path traversal in patch file headers that bypass file path validation, exposing the container or host filesystem to modification. This is a file system manipulation weakness classified as CWE-22.

pnpm versions prior to 10.34.0 and 11.4.0 are affected. The vulnerability exists in the @pnpm/patch-package module used by pnpm, a popular JavaScript package manager. Users running pnpm install in a repository that accepts patches from pull requests are at risk if the package manager is not updated.

The CVSS score of 7.3 indicates high severity, but the EPSS score is not available, so the current probability of exploitation is unclear. The vulnerability is not listed in the CISA KEV catalog. The attack vector relies on a malicious patch file that is submitted via a pull request, making it likely that project maintainers can exploit the flaw by accepting a PR that contains a crafted .patch file. Because the path traversal in the diff header is opaque to most code reviews, an attacker can evade manual detection and immediately write or delete critical files during dependency installation.