CVE-2018-20843: Canonical Ubuntu Linux

High severity, CVSS 7.5. EPSS: 7.1% chance of exploitation in the next 30 days.

In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).

Affected products

• Canonical Ubuntu Linux: version 12.04 only; version 14.04 only; version 16.04 only; version 18.04 only; version 18.10 only; version 19.04 only
• Debian Debian Linux: version 8.0 only; version 9.0 only
• Fedoraproject Fedora: version 29 only; version 30 only
• Libexpat Project Libexpat: before 2.2.7 (fixed in 2.2.7)
• Opensuse Leap: version 15.0 only; version 15.1 only
• Oracle Hospitality Res 3700: from 5.7, up to and including 5.7.6
• Oracle HTTP Server: version 12.1.3.0 only; version 12.2.1.4.0 only
• Oracle Outside In Technology: version 8.5.4 only; version 8.5.5 only
• Tenable Nessus: before 8.15.0 (fixed in 8.15.0)

Published 2019-06-24. Last modified 2026-06-17.