CVE-2016-4558: Canonical Ubuntu Linux

High severity, CVSS 7.0. EPSS: 0.9% chance of exploitation in the next 30 days.

The BPF subsystem in the Linux kernel before 4.5.5 mishandles reference counts, which allows local users to cause a denial of service (use-after-free) or possibly have unspecified other impact via a crafted application on (1) a system with more than 32 Gb of memory, related to the program reference count or (2) a 1 Tb system, related to the map reference count.

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only
• Linux Linux Kernel: from 4.4, before 4.4.11 (fixed in 4.4.11); from 4.5, before 4.5.5 (fixed in 4.5.5)

Published 2016-05-23. Last modified 2026-06-17.