High 7.9Published Jun 18, 2026

CVE-2026-42487x86 HVM I/O port list traversal

Updated under an hour ago (Oct 26, 2026, 1:20 PM ET)

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It affects Xen. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

HVM guest I/O port accesses are subject to either emulation or at least translation. Translations are managed by the device model (via XEN_DOMCTL_ioport_mapping), and hence the linked list used may changed at any time. Traversal of those lists (while handling guest I/O port accesses) therefore needs synchronizing with updates, which was missing so far.

CVSS: 7.9 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H
Weakness (CWE): CWE-362
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: XEN
NVD analysis: Deferred
Record last updated: Jun 18, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Xen Xen xen:xen (from the name)	consult Xen advisory XSA-491 status unknown	CNA record

References

References

https://xenbits.xenproject.org/xsa/advisory-491.html
http://www.openwall.com/lists/oss-security/2026/06/09/11
http://xenbits.xen.org/xsa/advisory-491.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.