CVE-2026-79609

UNKNOWN 0.0

x86: XPTI may break on huge-memory systems

CVSS Score

0.0

EPSS Score

0.0%

EPSS Percentile

0th

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.

Vendor	xen
Product	xen
Published	Oct 13, 2026
Last Updated	Oct 13, 2026

Stay Ahead of the Next One

Get instant alerts for xen xen

Be the first to know when new unknown vulnerabilities affecting xen xen are published — delivered to Slack, Telegram or Discord.

Get Free Alerts → Free · No credit card · 60 sec setup

Affected Versions

Xen / Xen

All versions affected

References

NVD ↗ CVE.org ↗ EPSS Data ↗

xenbits.xenproject.org: https://xenbits.xenproject.org/xsa/advisory-516.html xenbits.xen.org: http://xenbits.xen.org/xsa/advisory-516.html

Credits

This issue was discovered by George Dunlap.