pnpm up to 10.28.0 on Windows path traversal

Summaryinfo

A vulnerability was found in pnpm up to 10.28.0 on Windows. It has been classified as critical. This issue affects some unknown processing. This manipulation causes path traversal. This vulnerability is tracked as CVE-2026-23889. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in pnpm up to 10.28.0 on Windows. It has been declared as critical. Affected by this vulnerability is an unknown code block. The manipulation with an unknown input leads to a path traversal vulnerability. The CWE definition for the vulnerability is CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

pnpm is a package manager. Prior to version 10.28.1, a path traversal vulnerability in pnpm's tarball extraction allows malicious packages to write files outside the package directory on Windows. The path normalization only checks for `./` but not `.\`. On Windows, backslashes are directory separators, enabling path traversal. This vulnerability is Windows-only. This issue impacts Windows pnpm users and Windows CI/CD pipelines (GitHub Actions Windows runners, Azure DevOps). It can lead to overwriting `.npmrc`, build configs, or other files. Version 10.28.1 contains a patch.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-23889 since 01/16/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1006 according to MITRE ATT&CK.

Upgrading to version 10.28.1 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 6ca07ffbe6fc0e8b8cdc968f228903ba0886f7c0 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-4657). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

• pnpm

Version

• 10.0
• 10.1
• 10.2
• 10.3
• 10.4
• 10.5
• 10.6
• 10.7
• 10.8
• 10.9
• 10.10
• 10.11
• 10.12
• 10.13
• 10.14
• 10.15
• 10.16
• 10.17
• 10.18
• 10.19
• 10.20
• 10.21
• 10.22
• 10.23
• 10.24
• 10.25
• 10.26
• 10.27
• 10.28.0

License

• open-source

Website

• Product: https://github.com/pnpm/pnpm/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion