Buffer overflow in Xen

CVE-2026-42488

Some shadow paging errors paths will switch the page-tables without updating the currently running vCPU reference. This causes a mismatch between the loaded page-tables and the mapcache metadata which can lead to corruption of the mapcache.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (43.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 43.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-42488: held from 0.004 to 0.005.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.002

Affected products

  • Xen — versions consult Xen advisory XSA-494

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-42488?
CVE-2026-42488 is a high-severity vulnerability in Xen, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.1/10. Published 2026-06-18.
How severe is CVE-2026-42488?
High severity. CVSS v3 base score is 8.1 out of 10.