CVE-2016-7426: Canonical Ubuntu Linux

High severity, CVSS 7.5. EPSS: 12.4% chance of exploitation in the next 30 days.

NTP before 4.2.8p9 rate limits responses received from the configured sources when rate limiting for all associations is enabled, which allows remote attackers to cause a denial of service (prevent responses from the sources) by sending responses with a spoofed source address.

Affected products

• Canonical Ubuntu Linux: version 12.04 only
• HPE Hpux-Ntp: from b.11.31, before c.4.2.8.2.0 (fixed in c.4.2.8.2.0)
• Ntp Ntp: from 4.2.6, before 4.2.8 (fixed in 4.2.8); from 4.3.0, before 4.3.94 (fixed in 4.3.94); version 4.2.5 only; version 4.2.8 only
• Red Hat Enterprise Linux Desktop: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server Aus: version 7.3 only; version 7.4 only; version 7.6 only; version 7.7 only
• Red Hat Enterprise Linux Server Eus: version 7.3 only; version 7.4 only; version 7.5 only; version 7.6 only; version 7.7 only
• Red Hat Enterprise Linux Server Tus: version 7.3 only; version 7.6 only; version 7.7 only
• Red Hat Enterprise Linux Workstation: version 6.0 only; version 7.0 only

Published 2017-01-13. Last modified 2026-06-17.