Memory Leak Issue in Linux Kernel Affecting KVM on SEV-ES Guests

CVE-2026-53345

What is CVE-2026-53345?

A memory leak vulnerability exists in the Linux kernel, specifically related to the KVM virtualization technology used for SEV-ES guests. This issue arises when memory is marked as dirty without an active virtual CPU (vCPU) during the virtual machine's destruction process. When a guest page remains writable across a user space exit without a subsequent KVM_RUN call, it can lead to a scenario where the memory is not correctly unmapped upon vCPU termination. As a result, a warning is triggered unnecessarily, although userspace should not reach the dirty ring in this situation. This vulnerability may result in degraded performance and system stability, highlighting the need for timely patching and attention to KVM configurations.

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