# CVE-2026-42487: xen: HVM guest I/O port accesses are subject to either emulation or at least translation

CVE-2026-42487 is fixed in xen on 1 platform, first by SUSE-SU-2026:2329-1, released June 10, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-42487
- Priority: High
- CVSS: 7.9 (high)
- EPSS: 0.0010
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 10, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | xen Debian 12.15 (bookworm) | 4.17.7-0+deb12u1 | [DEBIAN-CVE-2026-42487](https://patchblox.com/security/data/fix/linux/debian-cve-2026-42487.md) | Jun 18, 2026 |
| Linux | xen Debian 13.5 (trixie) | 4.20.3+127-gc42374a105-0+deb13u1 | [DEBIAN-CVE-2026-42487](https://patchblox.com/security/data/fix/linux/debian-cve-2026-42487.md) | Jun 18, 2026 |
| Linux | xen Debian 14 | 4.20.3+127-gc42374a105-1 | [DEBIAN-CVE-2026-42487](https://patchblox.com/security/data/fix/linux/debian-cve-2026-42487.md) | Jun 18, 2026 |
| Linux | xen sles 15.6 | 4.18.5_18-150600.3.50.1 | [SUSE-SU-2026:2329-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2329-1.md) | Jun 10, 2026 |
| Linux | xen sles 15.7 | 4.20.3_06-150700.3.41.1 | [SUSE-SU-2026:2364-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2364-1.md) | Jun 11, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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