An off-by-one error was found in QEMU's KVM Xen guest support. A malicious guest could use this flaw to trigger out-of-bounds heap accesses in the QEMU process via the emulated Xen physdev hypercall interface, leading to a denial of service or potential memory corruption. Patch: https://lore.kernel.org/qemu-devel/13FE03BE60EA78D6+20260109023548.4047-1-vr@darknavy.com/ Credit: DARKNAVY (@DarkNavyOrg)