CVE-2018-15572: Canonical Ubuntu Linux

Medium severity, CVSS 6.5. EPSS: 0.5% chance of exploitation in the next 30 days.

The spectre_v2_select_mitigation function in arch/x86/kernel/cpu/bugs.c in the Linux kernel before 4.18.1 does not always fill RSB upon a context switch, which makes it easier for attackers to conduct userspace-userspace spectreRSB attacks.

Affected products

• Canonical Ubuntu Linux: version 12.04 only; version 14.04 only; version 16.04 only; version 18.04 only
• Debian Debian Linux: version 8.0 only; version 9.0 only
• Linux Linux Kernel: before 4.18.1 (fixed in 4.18.1)

Published 2018-08-20. Last modified 2026-06-17.