CVE-2026-55698: pnpm: Project env lockfile can short-circuit package-manager resolution and execute lockfile-selected pnpm bytes

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-06-25 · updated 2026-06-30
Weakness: CWE-345

Description

pnpm is a package manager. Prior to 10.34.2 and 11.5.3, pnpm can persist package-manager bootstrap metadata in the first YAML document of pnpm-lock.yaml. Before the patch, direct pnpm execution trusted an already resolved packageManagerDependencies entry when the committed env lockfile contained matching pnpm and @pnpm/exe versions. A malicious repository could therefore commit package-manager lockfile package records and snapshots that bypassed fresh package-manager resolution, then cause pnpm to install and execute bytes selected by that committed lockfile state during automatic version switching. This vulnerability is fixed in 10.34.2 and 11.5.3.

Affected products

pnpm: before 10.34.2; from 11.0.0 before 11.5.3 — fixed in 10.34.2, 11.5.3

How to fix

Upgrade to a fixed version: pnpm 10.34.2, 11.5.3. Check the vendor advisory for mitigations.

References

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