A path traversal flaw in pnpm's binary fetcher enables attackers to cause the extractor to write files outside the intended extraction directory. By including ZIP entries that contain ../ sequences or absolute paths, or by supplying a malicious BinaryResolution.prefix that is concatenated without validation, a package can overwrite arbitrary files. This flaw is classified under CWE-22, CWE-23 and CWE-426 and can lead to the replacement of configuration files, scripts, and other important assets, effectively enabling remote code execution on the node application environment.

All users of pnpm versions earlier than 10.28.1 who install packages that include binary assets are affected. This includes local developers, teams that accept external packages, and continuous‑integration or deployment workflows that automatically resolve and install binary dependencies. Custom Node.js binary configurations or named prefixes that developers configure are also susceptible if used with the affected pnpm release.

The CVSS score is 6.5, indicating medium severity. EPSS is reported as less than 1%, suggesting a low estimated exploitation probability, and the vulnerability is not listed in CISA’s KEV catalog. However, because the flaw allows an attacker who can supply a malicious package to write to arbitrary locations, it could lead to the execution of injected code once the malicious binary is executed. The likely attack vector is supply‑chain tampering during package installation, commonly via compromised or forged dependencies, which is a realistic threat for projects that fetch from public registries or use CI/CD pipelines that automatically install dependencies.