CVE-2026-79609

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 directmap is used. PV guests, however, have a directmap which may not cover all memory; in particular this is the case if any memory extends beyond the 5 TiB (CONFIG_BIGMEM=y: 3.5 TiB) address boundary.

Score
CVSS 3.1 8.8 High
Status
Awaiting Analysis - security@xen.org
Published
2026-10-13
Last modified
2026-10-20
Weaknesses
CWE-284

Affected products

References

 
 
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