CVE-2018-8777: Canonical Ubuntu Linux

High severity, CVSS 7.5. EPSS: 4.5% chance of exploitation in the next 30 days.

In Ruby before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1, an attacker can pass a large HTTP request with a crafted header to WEBrick server or a crafted body to WEBrick server/handler and cause a denial of service (memory consumption).

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only; version 17.10 only
• Debian Debian Linux: version 7.0 only; version 8.0 only; version 9.0 only
• Red Hat Enterprise Linux: version 6.0 only; version 7.0 only; version 7.4 only; version 7.5 only; version 7.6 only
• Ruby-Lang Ruby: from 2.2.0, before 2.2.10 (fixed in 2.2.10); from 2.3.0, before 2.3.7 (fixed in 2.3.7); from 2.4.0, before 2.4.4 (fixed in 2.4.4); from 2.5.0, before 2.5.1 (fixed in 2.5.1); version 2.6.0 only

Published 2018-04-03. Last modified 2026-06-17.