CVE-2018-20023: Canonical Ubuntu Linux

High severity, CVSS 7.5. EPSS: 2.5% chance of exploitation in the next 30 days.

LibVNC before 8b06f835e259652b0ff026898014fc7297ade858 contains CWE-665: Improper Initialization vulnerability in VNC Repeater client code that allows attacker to read stack memory and can be abuse for information disclosure. Combined with another vulnerability, it can be used to leak stack memory layout and in bypassing ASLR

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.