| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| [This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]
With the introduction of Grant Table v2 came the requirement to be able to
switch between versions. Switching from v1 to v2 reduces the number of
valid grant references, as a bigger shared entry structure is then needed
while the shared table doesn't change size. Switching from v2 back to v1
the status frames, which are separate in v2, go away.
Code holding, but intermediately dropping and then re-acquiring the grant
table lock, sometimes wrongly assumes that said properties wouldn't change
across the window in time where the lock is not being held.
The v1 -> v2 issue is CVE-2026-62435.
The v2 -> v1 issue is CVE-2026-62436. |
| The EVTCHNOP_expand_array hypercall checks for whether FIFO event
channels are enabled, but without holding the correct lock. It can race
with EVTCHNOP_reset, resulting in dereferencing a NULL pointer. |
| [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. |
| A guest started with Populated on Demand enabled (PoD) can attempt to
reclaim pages which aren't regular guest RAM. This can cause corruption
of memory management state in Xen. |
| [This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]
With the introduction of Grant Table v2 came the requirement to be able to
switch between versions. Switching from v1 to v2 reduces the number of
valid grant references, as a bigger shared entry structure is then needed
while the shared table doesn't change size. Switching from v2 back to v1
the status frames, which are separate in v2, go away.
Code holding, but intermediately dropping and then re-acquiring the grant
table lock, sometimes wrongly assumes that said properties wouldn't change
across the window in time where the lock is not being held.
The v1 -> v2 issue is CVE-2026-62435.
The v2 -> v1 issue is CVE-2026-62436. |
| 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.]
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. |
| [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. |
| Some shadow paging errors paths will switch the page-tables without
updating the currently running vCPU reference. This causes a mismatch
between the loaded page-tables and the mapcache metadata which can lead
to corruption of the mapcache. |
| 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. |
| Xen allows guest OS users to obtain sensitive information from uninitialized locations in host OS kernel memory by not enabling memory and I/O decoding control bits. NOTE: this vulnerability exists because of an incomplete fix for CVE-2015-0777. |
| Any guest can cause xenstored to crash by issuing a XS_RESET_WATCHES
command within a transaction due to an assert() triggering.
In case xenstored was built with NDEBUG #defined nothing bad will
happen, as assert() is doing nothing in this case. Note that the
default is not to define NDEBUG for xenstored builds even in release
builds of Xen. |
| The adjustments made for XSA-379 as well as those subsequently becoming
XSA-387 still left a race window, when a HVM or PVH guest does a grant
table version change from v2 to v1 in parallel with mapping the status
page(s) via XENMEM_add_to_physmap. Some of the status pages may then be
freed while mappings of them would still be inserted into the guest's
secondary (P2M) page tables. |
