CVE-2026-42487

EUVD-2026-37888
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.
Race Condition
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7.9 HIGH
LOCAL
LOW
LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Debian logo
Debian Releases
Debian Product
Codename
xen
bookworm
vulnerable
bookworm (security)
vulnerable
bullseye
vulnerable
bullseye (security)
vulnerable
forky
vulnerable
sid
vulnerable
trixie
vulnerable
trixie (security)
vulnerable
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
xen
bionic
needs-triage
focal
needs-triage
jammy
needs-triage
noble
needs-triage
questing
needs-triage
resolute
needs-triage
xenial
needs-triage
Common Weakness Enumeration
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