Data Handling Vulnerability in KVM for Linux Kernel by QEMU

CVE-2026-63806

What is CVE-2026-63806?

A vulnerability in the KVM component of the Linux kernel allowed for the potential triggering of a BUG_ON() condition due to improper data alignment during memory access operations. This issue, which had been present since 2009, affected how KVM processed stores that split across multiple pages, particularly in cases with emulated MMIO. A dedicated fix replaced the problematic checks with more reliable alignment handling, ensuring safer data processing within the virtualization environment.

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