CVE-2026-79609

The Xen hypervisor contains a vulnerability where XPTI (Xen Page Table Isolation) may break on huge-memory systems . This occurs because PV guests use a directmap that may not cover all memory if any memory extends beyond the 5 TiB (CONFIG_BIGMEM=y: 3.5 TiB) address boundary during the copying of...

CVE-2026-79609 x86: XPTI may break on huge-memory systems

XPTI Xen Page Table Isolation was introduced to mitigate Meltdown CVE-2017-5754, one aspect of XSA-254. This involves copying 64-bit PV guest page table entries from guest-chosen root page tables to the Xen- chosen one which is in actual use by hardware. To read the guest root page table, the...

CVE-2026-79609 x86: XPTI may break on huge-memory systems

XPTI Xen Page Table Isolation was introduced to mitigate Meltdown CVE-2017-5754, one aspect of XSA-254. This involves copying 64-bit PV guest page table entries from guest-chosen root page tables to the Xen- chosen one which is in actual use by hardware. To read the guest root page table, the...