CVE-2026-55700: pnpm: stage download writes outside destination via manifest version traversal

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-06-25 · updated 2026-06-29
Weakness: CWE-22

Description

pnpm is a package manager. From 11.3.0 until 11.5.3, `pnpm stage download` derived a local filename from registry-controlled package name and version fields. A crafted manifest could escape the selected download directory and overwrite another reachable file. The merged fix validates both fields, derives one safe filename, and verifies the final destination before writing. This vulnerability is fixed in 11.5.3.

Affected products

pnpm: from 11.3.0 before 11.5.3 — fixed in 11.5.3

How to fix

Upgrade to a fixed version: pnpm 11.5.3. Check the vendor advisory for mitigations.

References

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