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
4.20.3+127-gc42374a105-1
fixed
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
ignored
resolute
needs-triage
xenial
needs-triage
Common Weakness Enumeration
Vulnerability Media Exposure
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