CVE-2018-20020: Canonical Ubuntu Linux

Critical severity, CVSS 9.8. EPSS: 8.6% chance of exploitation in the next 30 days.

LibVNC before commit 7b1ef0ffc4815cab9a96c7278394152bdc89dc4d contains heap out-of-bound write vulnerability inside structure in VNC client code that can result remote code execution

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only; version 18.04 only; version 18.10 only
• Debian Debian Linux: version 8.0 only; version 9.0 only
• Libvnc Project Libvncserver: before 0.9.12 (fixed in 0.9.12)

Published 2018-12-19. Last modified 2026-06-17.