CVE-2015-0239: The em_sysenter function in arch/x86/kvm/emulate.c in the Linux kernel before 3.18.5, when the guest OS lac...

Security readout for executives and security teams

CVE-2015-0239 is a Linux KVM virtualization bug. A user inside a guest virtual machine could trigger a broken SYSENTER emulation path and potentially gain higher privileges inside that guest or crash it. The provided sources do not indicate host escape or active exploitation. Exposure is most relevant to Linux virtualization hosts running KVM with kernels before 3.18.5 or vendor kernels lacking the referenced backport. Risk is higher where guest users are untrusted or where guest availability matters. Treat this as a virtualization platform maintenance issue, not an internet-wide emergency. Patch affected KVM hosts on a normal security timeline, faster for multi-tenant or untrusted guest environments. Mitigation focus: Update affected Linux kernels using the relevant vendor security advisory.; Confirm the fix or backport includes Linux commit f3747379accba8e95d70cec0eae0582c8c182050.; Prioritize KVM hosts with untrusted guest workloads or shared tenancy..

Prepared

Jun 14, 2026, 05:11 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.