| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| Accessing the vNUMA configuration data of a guest is still possible when
domain destruction has already started. The cleaning up of that
configuration information is not synchronized with its retrieval by a
device model controlling the guest. |
| Accesses to the CMOS memory contents are done using an indirect IO port
pair. Therefore Xen needs to cache the guest chosen index, and one of
the usages of the index didn't take the necessary locking to avoid
concurrent changes. As a result, a guest could change the index after
it being checked, causing a subsequent out-of-bound read access to the
contents of an array. |
| The logic to handle periodic Viridian STIMERs performs a division with an
unchecked user-controlled divisor value, that can be set to zero to cause a #DE
fault. |
| Parts of the DM_OP handling code assumes the caller has provided the
required number of buffers for the given operation without any checking
being done. As a result, certain operations might access stack
rubble as structures are possibly uninitialized. |
| Xenstore, to have an up-to-date picture of the entire system, wants to
know of domains appearing and disappearing. To make this more robust, a
new XEN_DOMCTL_get_domain_state was introduced. The management of the
bitmap underlying that operation is tied into the binding of the
VIRQ_DOM_EXC virtual IRQ. Unfortunately an error path there would tear
down the bitmap even in cases when it wasn't set up. Unprivileged domains
can trigger that error path. |
| [This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]
The directory and Rock Ridge / SUSP walk in libfsimage's iso9660 driver
derives several lengths directly from attacker-controlled on-disk fields
without validating them:
* The directory loop itself assumes a good record length. This is
CVE-2026-42494.
* The calculation of the System Use area may underflow. This is
CVE-2026-42495.
* The Rock Ridge extension loop assumes a good (inner) record length.
This is CVE-2026-62423.
* The Rock Ridge NM record processing assumes a good entry length.
This is CVE-2026-62424.
* The Rock Ridge CE record processing assumes a good size and offset.
This is CVE-2026-62425. |
| [This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]
The directory and Rock Ridge / SUSP walk in libfsimage's iso9660 driver
derives several lengths directly from attacker-controlled on-disk fields
without validating them:
* The directory loop itself assumes a good record length. This is
CVE-2026-42494.
* The calculation of the System Use area may underflow. This is
CVE-2026-42495.
* The Rock Ridge extension loop assumes a good (inner) record length.
This is CVE-2026-62423.
* The Rock Ridge NM record processing assumes a good entry length.
This is CVE-2026-62424.
* The Rock Ridge CE record processing assumes a good size and offset.
This is CVE-2026-62425. |
| [This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]
The directory and Rock Ridge / SUSP walk in libfsimage's iso9660 driver
derives several lengths directly from attacker-controlled on-disk fields
without validating them:
* The directory loop itself assumes a good record length. This is
CVE-2026-42494.
* The calculation of the System Use area may underflow. This is
CVE-2026-42495.
* The Rock Ridge extension loop assumes a good (inner) record length.
This is CVE-2026-62423.
* The Rock Ridge NM record processing assumes a good entry length.
This is CVE-2026-62424.
* The Rock Ridge CE record processing assumes a good size and offset.
This is CVE-2026-62425. |
| [This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.]
The Windows PV drivers expose various facilities to userspace. Several
of these have no security descriptor, and are therefore fully accessible
to unprivileged users. These are:
1. XenCons, CVE-2025-27462
2. XenIface, CVE-2025-27463
3. XenBus, CVE-2025-27464 |
| [This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] The Windows PV drivers expose various facilities to userspace. Several of these have no security descriptor, and are therefore fully accessible to unprivileged users. These are: 1. XenCons, CVE-2025-27462 2. XenIface, CVE-2025-27463 3. XenBus, CVE-2025-27464 |
| [This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] The Windows PV drivers expose various facilities to userspace. Several of these have no security descriptor, and are therefore fully accessible to unprivileged users. These are: 1. XenCons, CVE-2025-27462 2. XenIface, CVE-2025-27463 3. XenBus, CVE-2025-27464 |
| varstored is a component of the Xapi toolstack handling UEFI Variables
for a VM. It has a communication path with OVMF inside the VM involving
mapping a buffer prepared by OVMF.
Within varstored, there were insufficient compiler barriers, creating
TOCTOU issues with data in the shared buffer.
The exact vulnerable behaviour depends on the code generated by the
compiler. In a build of varstored using default settings, the attacker
can control an index used in a jump table. |
| When oxenstored is tearing a domain down, the node data is cleaned up
but the usage counts are leaked.
When the domain ID is eventually reused, the new domain can create fewer
nodes before beeing deemed to be over quota. |
| There 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. |
| [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. |
| [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. |
| [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. |
| [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. |
| [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. |
| [This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]
To create and manage guests, domctl operations are used by the control
domain, a possible Xenstore domain, or by a domain controlling a
particular guest. Some of these operations may not be executed in
parallel, so a system-wide lock is used. The way that lock is acquired
is, however, not providing any fairness. This is CVE-2026-42489.
Furthermore, with XSM/Flask in use, the lock acquire will, for some
operations, occur ahead of any permission checking. This is
CVE-2026-42490. |
