CVE-2018-9234: Canonical Ubuntu Linux

High severity, CVSS 7.5. EPSS: 2% chance of exploitation in the next 30 days.

GnuPG 2.2.4 and 2.2.5 does not enforce a configuration in which key certification requires an offline master Certify key, which results in apparently valid certifications that occurred only with access to a signing subkey.

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only; version 17.10 only; version 18.04 only
• Gnupg Gnupg: version 2.2.4 only; version 2.2.5 only

Published 2018-04-04. Last modified 2026-06-17.