{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-42487","assignerOrgId":"23aa2041-22e1-471f-9209-9b7396fa234f","state":"PUBLISHED","assignerShortName":"XEN","dateReserved":"2026-04-27T14:20:24.138Z","datePublished":"2026-06-18T13:46:53.459Z","dateUpdated":"2026-06-18T15:07:31.335Z"},"containers":{"cna":{"title":"x86 HVM I/O port list traversal","datePublic":"2026-06-09T12:00:00.000Z","descriptions":[{"lang":"en","value":"HVM guest I/O port accesses are subject to either emulation or at least\ntranslation.  Translations are managed by the device model (via\nXEN_DOMCTL_ioport_mapping), and hence the linked list used may changed\nat any time.  Traversal of those lists (while handling guest I/O port\naccesses) therefore needs synchronizing with updates, which was missing\nso far."}],"impacts":[{"descriptions":[{"lang":"en","value":"A device model of a HVM guest can cause a hypervisor crash, causing a\nDenial of Service (DoS) of the entire host.  Privilege escalation and\ninformation leaks cannot be ruled out."}]}],"affected":[{"defaultStatus":"unknown","product":"Xen","vendor":"Xen","versions":[{"status":"unknown","version":"consult Xen advisory XSA-491"}]}],"configurations":[{"lang":"en","value":"All Xen versions from at least 3.2 onwards are vulnerable.  Earlier\nversions have not been inspected.\n\nOnly x86 systems are vulnerable.  Arm systems are not vulnerable.\n\nOnly entities controlling HVM guests can leverage the vulnerability.\nThese are device models running in either a stub domain or de-privileged\nin Dom0."}],"workarounds":[{"lang":"en","value":"Running only PV or PVH guests will avoid the vulnerability.\n\n(Switching from a device model stub domain or a de-privileged device\nmodel to a fully privileged Dom0 device model does NOT mitigate this\nvulnerability.  Rather, it simply recategorises the vulnerability to\nhostile management code, regarding it \"as designed\"; thus it merely\nreclassifies these issues as \"not a bug\".  The security of a Xen system\nusing stub domains is still better than with a qemu-dm running as a Dom0\nprocess.  Users and vendors of stub qemu dm systems should not change\ntheir configuration to use a Dom0 qemu process.)"}],"credits":[{"lang":"en","type":"finder","value":"This issue was discovered by Jan Beulich of SUSE."}],"references":[{"url":"https://xenbits.xenproject.org/xsa/advisory-491.html"}],"providerMetadata":{"orgId":"23aa2041-22e1-471f-9209-9b7396fa234f","shortName":"XEN","dateUpdated":"2026-06-18T13:46:53.459Z"}},"adp":[{"problemTypes":[{"descriptions":[{"type":"CWE","cweId":"CWE-362","lang":"en","description":"CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')"}]}],"metrics":[{"cvssV3_1":{"scope":"CHANGED","version":"3.1","baseScore":7.9,"attackVector":"LOCAL","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H","integrityImpact":"LOW","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"LOW"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-06-18T14:35:06.701148Z","id":"CVE-2026-42487","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-06-18T14:35:11.262Z"}},{"title":"CVE Program Container","references":[{"url":"http://xenbits.xen.org/xsa/advisory-491.html"},{"url":"http://www.openwall.com/lists/oss-security/2026/06/09/11"}],"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2026-06-18T15:07:31.335Z"}}]}}