CVE-2015-0239: Canonical Ubuntu Linux

Medium severity, CVSS 4.4. EPSS: 0.6% chance of exploitation in the next 30 days.

The em_sysenter function in arch/x86/kvm/emulate.c in the Linux kernel before 3.18.5, when the guest OS lacks SYSENTER MSR initialization, allows guest OS users to gain guest OS privileges or cause a denial of service (guest OS crash) by triggering use of a 16-bit code segment for emulation of a SYSENTER instruction.

Affected products

• Canonical Ubuntu Linux: version 12.04 only; version 14.04 only; version 14.10 only
• Debian Debian Linux: version 7.0 only; version 8.0 only
• Linux Linux Kernel: before 3.18.5 (fixed in 3.18.5)
• Oracle Linux: version 5 only; version 7 only
• Red Hat Enterprise Linux Desktop: version 6.0 only
• Red Hat Enterprise Linux Server: version 6.0 only
• Red Hat Enterprise Linux Workstation: version 6.0 only

Published 2015-03-02. Last modified 2026-06-17.