Memory Handling Vulnerability in Xen Hypervisor for x86 PV Guests

CVE-2026-79603

What is CVE-2026-79603?

The vulnerability allows x86 para-virtualized (PV) guests to free memory pages while a stale Translation Lookaside Buffer (TLB) entry still points to those pages. If the memory is scrubbed prior to the necessary TLB flush, it creates a potential window for the PV guest to alter a page that has already been cleared. This could result in unauthorized access or modification of data, posing a significant security risk. It is essential for users and administrators to apply any relevant patches or mitigations to safeguard their systems.

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