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Fencer Vulns
medium 6.5

CVE-2026-23888 json

pnpm: Binary ZIP extraction allows arbitrary file write via path traversal (Zip Slip)

published 2026-01-26 9 mo ago modified 2026-06-17 4 mo ago also GHSA-6pfh-p556-v868 , EUVD-2026-4655

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 39%
public exploits
0
none known

Summary

pnpm is a package manager. Prior to version 10.28.1, a path traversal vulnerability in pnpm's binary fetcher allows malicious packages to write files outside the intended extraction directory. The vulnerability has two attack vectors: (1) Malicious ZIP entries containing `../` or absolute paths that escape the extraction root via AdmZip's `extractAllTo`, and (2) The `BinaryResolution.prefix` field is concatenated into the extraction path without validation, allowing a crafted prefix like `../../evil` to redirect extracted files outside `targetDir`. The issue impacts all pnpm users who install packages with binary assets, users who configure custom Node.js binary locations and CI/CD pipelines that auto-install binary dependencies. It can lead to overwriting config files, scripts, or other sensitive files leading to RCE. Version 10.28.1 contains a patch.

Patch / fix

  • npm pnpm 10.28.1
  • pnpm pnpm 10.28.1
  • pnpm Alpine 3.23 10.33.4-r0

alpine advisories ALPINE-CVE-2026-23888

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-23888 updated cvss 6.5

pnpm: pnpm: Arbitrary file write via path traversal in binary fetcher leading to remote code execution

  • Red Hat JBoss Enterprise Application Platform 8 org.keycloak-keycloak-parent Red Hat JBoss Enterprise Application Platform Expansion Pack org.keycloak-keycloak-parent
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
9 mo ago

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/pnpm/pnpm/security/advisories/GHSA-6pfh-p556-v868 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
npm pnpm
<10.28.1
10.28.1

Affected products

  • pnpm pnpm

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory
  • CWE-23 Relative Path Traversal
  • CWE-426 Untrusted Search Path

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.