CVE-2018-12556: Yarnpkg Website

Medium severity, CVSS 5.9. EPSS: 1.8% chance of exploitation in the next 30 days.

The signature verification routine in install.sh in yarnpkg/website through 2018-06-05 only verifies that the yarn release is signed by any (arbitrary) key in the local keyring of the user, and does not pin the signature to the yarn release key, which allows remote attackers to sign tampered yarn release packages with their own key.

Affected products

• Yarnpkg Website: up to and including 2018-06-05

Published 2019-05-16. Last modified 2026-06-17.