Xen Xapi vulnerabilities
8 vulnerabilities
Known vulnerabilities in Xen Xapi, newest first, with CVSS severity, EPSS, KEV listings, ransomware use and the affected versions.
PrioritiseCVE-2026-42486xen · xapi +1 moreMultiple RBAC issues in XAPI[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:
https://docs.xenserver.com/en-us/xencenter/current-release/rbac-overview.html#rbac-roles
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.
* 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.CVSS9.4CriticalEPSS0.17%PrioritiseCVE-2026-23562xen · xapi +1 moreMultiple RBAC issues in XAPI[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:
https://docs.xenserver.com/en-us/xencenter/current-release/rbac-overview.html#rbac-roles
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.
* 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.CVSS9.4CriticalEPSS0.17%PrioritiseCVE-2026-23561xen · xapi +1 moreMultiple RBAC issues in XAPI[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:
https://docs.xenserver.com/en-us/xencenter/current-release/rbac-overview.html#rbac-roles
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.
* 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.CVSS9.4CriticalEPSS0.17%PrioritiseCVE-2026-23560xen · xapi +1 moreMultiple RBAC issues in XAPI[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:
https://docs.xenserver.com/en-us/xencenter/current-release/rbac-overview.html#rbac-roles
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.
* 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.CVSS9.4CriticalEPSS0.17%PrioritiseCVE-2026-23559xen · xapi +1 moreMultiple RBAC issues in XAPI[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:
https://docs.xenserver.com/en-us/xencenter/current-release/rbac-overview.html#rbac-roles
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.
* 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.CVSS9.4CriticalEPSS0.17%PrioritiseCVE-2025-58146xen · xapi +1 moreXAPI UTF-8 string handlingThere are multiple issues.
1. Updates to the XAPI database sanitise input strings, but try
generating the notification using the unsanitised input. This
causes the database's event thread to terminate and cease further
processing.
2. XAPI's UTF-8 encoder implements v3.0 of the Unicode spec, but XAPI
uses libraries which conform to the stricter v3.1 of the Unicode
spec. This causes some strings to be accepted as valid UTF-8 by
XAPI, but rejected by other libraries in use. Notably, such strings
can be entered into the database, after which the database can no
longer be loaded.
3. There is no input sanitisation for Map/Set updates on objects in the
XAPI database.CVSS9.4CriticalEPSS0.18%RoutineCVE-2024-31144xen · xapi +1 moreXapi: Metadata injection attack against backup/restore functionalityFor a brief summary of Xapi terminology, see:
https://xapi-project.github.io/xen-api/overview.html#object-model-overview
Xapi contains functionality to backup and restore metadata about Virtual
Machines and Storage Repositories (SRs).
The metadata itself is stored in a Virtual Disk Image (VDI) inside an
SR. This is used for two purposes; a general backup of metadata
(e.g. to recover from a host failure if the filer is still good), and
Portable SRs (e.g. using an external hard drive to move VMs to another
host).
Metadata is only restored as an explicit administrator action, but
occurs in cases where the host has no information about the SR, and must
locate the metadata VDI in order to retrieve the metadata.
The metadata VDI is located by searching (in UUID alphanumeric order)
each VDI, mounting it, and seeing if there is a suitable metadata file
present. The first matching VDI is deemed to be the metadata VDI, and
is restored from.
In the general case, the content of VDIs are controlled by the VM owner,
and should not be trusted by the host administrator.
A malicious guest can manipulate its disk to appear to be a metadata
backup.
A guest cannot choose the UUIDs of its VDIs, but a guest with one disk
has a 50% chance of sorting ahead of the legitimate metadata backup. A
guest with two disks has a 75% chance, etc.CVSS3.8LowEPSS0.21%PrioritiseCVE-2020-29487xen · xapixen xapiAn issue was discovered in Xen XAPI before 2020-12-15. Certain xenstore keys provide feedback from the guest, and are therefore watched by toolstack. Specifically, keys are watched by xenopsd, and data are forwarded via RPC through message-switch to xapi. The watching logic in xenopsd sends one RPC update containing all data, any time any single xenstore key is updated, and therefore has O(N^2) time complexity. Furthermore, message-switch retains recent (currently 128) RPC messages for diagnostic purposes, yielding O(M*N) space complexity. The quantity of memory a single guest can monopolise is bounded by xenstored quota, but the quota is fairly large. It is believed to be in excess of 1G per malicious guest. In practice, this manifests as a host denial of service, either through message-switch thrashing against swap, or OOMing entirely, depending on dom0's configuration. (There are no quotas in xenopsd to limit the quantity of keys that result in RPC traffic.) A buggy or malicious guest can cause unreasonable memory usage in dom0, resulting in a host denial of service. All versions of XAPI are vulnerable. Systems that are not using the XAPI toolstack are not vulnerable.CVSS7.8HighEPSS1.45%