7.9

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

Deferred
AliasesALPINE-CVE-2026-42487UBUNTU-CVE-2026-42487DEBIAN-CVE-2026-42487
Published 18-06-2026Last modified 18-06-2026

Vulnerability summary

CVE-2026-42487 is a high (CVSS 7.9) vulnerability in xen. EPSS estimates a 0.10% chance of exploitation in the next 30 days, higher than 0.6% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.9, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.9/10
010
High · v3.1 (CVE.org)
EPSS score
0.10%
0%100%
Low · -0.03 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 5 · Related 5
SUSE-SU-2026:2328-1SUSE-SU-2026:2329-1SUSE-SU-2026:2364-1SUSE-SU-2026:2613-1SUSE-SU-2026:2668-1

Timeline

  1. 18-06-2026
    PublishedVulnerability first disclosed.
  2. 18-06-2026
    Last modifiedVulnerability information updated.

Description

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 metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.10%

Chance of exploitation in the next 30 days

Percentile

1%

Versus all other CVEs

30-day change

Decrease -0.03 pp

From 0.12% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Alpine1 product
  • xen< 4.18.5-r9 | < 4.19.5-r4 | < 4.20.3-r4 | < 4.21.1-r6
Debian1 product
  • xen< 4.17.7-0+deb12u1 | < 4.20.3+127-gc42374a105-0+deb13u1 | < 4.20.3+127-gc42374a105-1
Ubuntu1 product
  • xenAll versions (No fix recorded)

3 vendors · 3 products

References

8 links