CVE-2026-23559
[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.]
XAPI can configure different users with different roles, using Role Based Access Control. For more details, see:
The pool-admin role is fully privileged. Notably, users with this role can also SSH into the host as root.
The other administrator roles are pool-operator, vm-power-admin and vm-admin, each of which are authorised to configure and manage various aspects of the system.
Some settings are inadequately restricted, and can be set by a lower privilege of administrator than expected.
Detalles técnicos trazas, registros y código del informe original
https://docs.xenserver.com/en-us/xencenter/current-release/rbac-overview.html#rbac-roles * CVE-2026-23559: A vm-admin can set VBD.other_config:backend-local and turn arbitrary files in dom0 into VDIs (virtual disks) and give said disks to a VM they control. This is an arbitrary read and/or modify of files in dom0. * CVE-2026-23560: A vm-admin can set VM.other-config:is_system_domain and mark a VM as a system domain. System domains are ignored and left running during certain other host/pool operations, and may be hidden from view in tooling. * CVE-2026-23561: A vm-admin can set VM.other_config:storage_driver_domain and mark a VM as the storage domain for a particular host storage connection (PBD). Shutting down the VM can cause the PBD to be erroneously marked as unplugged when it is not. * CVE-2026-23562: Configuration of PCI passthrough is normally restricted to the pool-admin role. However one API was missing this check, allowing a vm-admin access to unintended host hardware. * CVE-2026-42486: A vm-admin can set the VM.platform:hvm_serial parameter, which should be restricted to the pool-admin role, as it can allow arbitrary dom0 file write.
CVSS
- Versión: 4.0
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Puntuación base: 9.4
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.17%
- Percentil entre todas las CVEs puntuadas: 5
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation85 % - Impacto principal
T1005Data from Local Systemcollection80 % - Impacto secundario
T1565.001Stored Data Manipulationimpact75 %
Acceso local (AV:L) sin interacción del usuario permite a usuario vm-admin escalar privilegios mediante configuraciones XAPI inadequadamente restringidas (VBD.other_config, VM.platform:hvm_serial) para leer/modificar archivos dom0 y obtener acceso root.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-250
Referencias
JSON original (NVD)
Mostrar
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"affected": [
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"published": "2026-07-09T16:16:38.807",
"references": [
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"source": "security@xen.org"
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"value": "[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.]\n\n\nXAPI can configure different users with different roles, using Role\nBased Access Control. For more details, see:\n\n https://docs.xenserver.com/en-us/xencenter/current-release/rbac-overview.html#rbac-roles \n\nThe pool-admin role is fully privileged. Notably, users with this role\ncan also SSH into the host as root.\n\nThe other administrator roles are pool-operator, vm-power-admin and\nvm-admin, each of which are authorised to configure and manage various\naspects of the system.\n\nSome settings are inadequately restricted, and can be set by a lower\nprivilege of administrator than expected.\n\n * CVE-2026-23559: A vm-admin can set VBD.other_config:backend-local and\n turn arbitrary files in dom0 into VDIs (virtual disks) and give said\n disks to a VM they control. This is an arbitrary read and/or modify\n of files in dom0.\n\n * CVE-2026-23560: A vm-admin can set VM.other-config:is_system_domain\n and mark a VM as a system domain. System domains are ignored and\n left running during certain other host/pool operations, and may be\n hidden from view in tooling.\n\n * CVE-2026-23561: A vm-admin can set VM.other_config:storage_driver_domain\n and mark a VM as the storage domain for a particular host storage\n connection (PBD). Shutting down the VM can cause the PBD to be\n erroneously marked as unplugged when it is not.\n\n * CVE-2026-23562: Configuration of PCI passthrough is normally\n restricted to the pool-admin role. However one API was missing this\n check, allowing a vm-admin access to unintended host hardware.\n\n * CVE-2026-42486: A vm-admin can set the VM.platform:hvm_serial\n parameter, which should be restricted to the pool-admin role, as it\n can allow arbitrary dom0 file write."
}
],
"lastModified": "2026-07-09T17:16:58.487",
"sourceIdentifier": "security@xen.org"
}