x86: XPTI may break on huge-memory systems (Xen Xen)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.11 % · percentile 1 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- XEN
- NVD status
- Awaiting Analysis
Description
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.
Weaknesses (CWE)
- CWE-284 — Improper Access Control
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 8.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H | CISA-ADP |
| CVSS 3.1 | HIGH 8.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H | NVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary) |
European references
- ENISA EUVD · EUVD-2026-98825
- GCVE · GCVE-0-2026-79609
CERT-FR advisories
- CERTFR-2026-AVI-1302 — Multiples vulnérabilités dans Xen · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| Xen · Xen | unknown consult Xen advisory XSA-516 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |