Path traversal in pnpm - CVE-2026-23889
Published: April 27, 2026
Vulnerability identifier: #VU128183
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-23889
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: pnpm
Affected software:
pnpm
pnpm
Detailed vulnerability description
The vulnerability allows a remote attacker to write arbitrary files outside the package directory.
The vulnerability exists due to path traversal in tarball extraction in store/cafs/src/parseTarball.ts when processing a crafted tarball on Windows. A remote attacker can supply a specially crafted package tarball with backslash-based traversal sequences to write arbitrary files outside the package directory.
User interaction is required to install the crafted package, and the issue is specific to Windows systems where backslashes are treated as directory separators.
How to mitigate CVE-2026-23889
Install security update from vendor's website.