| 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.]
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. |
| The pyGrub boot loader in Xen 3.0.3, 3.3.0, and Xen-3.3.1 does not support the password option in grub.conf for para-virtualized guests, which allows attackers with access to the para-virtualized guest console to boot the guest or modify the guest's kernel boot parameters without providing the expected password. |
| The hypervisor_callback function in Xen, possibly before 3.4.0, as applied to the Linux kernel 2.6.30-rc4, 2.6.18, and probably other versions allows guest user applications to cause a denial of service (kernel oops) of the guest OS by triggering a segmentation fault in "certain address ranges." |
| qemu-dm.debug in Xen 3.2.1 allows local users to overwrite arbitrary files via a symlink attack on the /tmp/args temporary file. |
| Heap-based buffer overflow in the flask_security_label function in Xen 3.3, when compiled with the XSM:FLASK module, allows unprivileged domain users (domU) to execute arbitrary code via the flask_op hypercall. |
| The AdSanity plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the 'ajax_upload' function in versions up to, and including, 1.8.1. This makes it possible for authenticated attackers with Contributor+ level privileges to upload arbitrary files on the affected sites server which makes remote code execution possible. |
| The Intel EPT paging code uses an optimization to defer flushing of any cached
EPT state until the p2m lock is dropped, so that multiple modifications done
under the same locked region only issue a single flush.
Freeing of paging structures however is not deferred until the flushing is
done, and can result in freed pages transiently being present in cached state.
Such stale entries can point to memory ranges not owned by the guest, thus
allowing access to unintended memory regions. |
| Any guest issuing a Xenstore command accessing a node using the
(illegal) node path "/local/domain/", will crash xenstored due to a
clobbered error indicator in xenstored when verifying the node path.
Note that the crash is forced via a failing assert() statement in
xenstored. In case xenstored is being built with NDEBUG #defined,
an unprivileged guest trying to access the node path "/local/domain/"
will result in it no longer being serviced by xenstored, other guests
(including dom0) will still be serviced, but xenstored will use up
all cpu time it can get. |
| Shadow mode tracing code uses a set of per-CPU variables to avoid
cumbersome parameter passing. Some of these variables are written to
with guest controlled data, of guest controllable size. That size can
be larger than the variable, and bounding of the writes was missing. |
| In the context switch logic Xen attempts to skip an IBPB in the case of
a vCPU returning to a CPU on which it was the previous vCPU to run.
While safe for Xen's isolation between vCPUs, this prevents the guest
kernel correctly isolating between tasks. Consider:
1) vCPU runs on CPU A, running task 1.
2) vCPU moves to CPU B, idle gets scheduled on A. Xen skips IBPB.
3) On CPU B, guest kernel switches from task 1 to 2, issuing IBPB.
4) vCPU moves back to CPU A. Xen skips IBPB again.
Now, task 2 is running on CPU A with task 1's training still in the BTB. |
| When passing through PCI devices, the detach logic in libxl won't remove
access permissions to any 64bit memory BARs the device might have. As a
result a domain can still have access any 64bit memory BAR when such
device is no longer assigned to the domain.
For PV domains the permission leak allows the domain itself to map the memory
in the page-tables. For HVM it would require a compromised device model or
stubdomain to map the leaked memory into the HVM domain p2m. |
| [This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]
Some Viridian hypercalls can specify a mask of vCPU IDs as an input, in
one of three formats. Xen has boundary checking bugs with all three
formats, which can cause out-of-bounds reads and writes while processing
the inputs.
* CVE-2025-58147. Hypercalls using the HV_VP_SET Sparse format can
cause vpmask_set() to write out of bounds when converting the bitmap
to Xen's format.
* CVE-2025-58148. Hypercalls using any input format can cause
send_ipi() to read d->vcpu[] out-of-bounds, and operate on a wild
vCPU pointer. |
| [This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]
Some Viridian hypercalls can specify a mask of vCPU IDs as an input, in
one of three formats. Xen has boundary checking bugs with all three
formats, which can cause out-of-bounds reads and writes while processing
the inputs.
* CVE-2025-58147. Hypercalls using the HV_VP_SET Sparse format can
cause vpmask_set() to write out of bounds when converting the bitmap
to Xen's format.
* CVE-2025-58148. Hypercalls using any input format can cause
send_ipi() to read d->vcpu[] out-of-bounds, and operate on a wild
vCPU pointer. |
| PVH guests have their ACPI tables constructed by the toolstack. The
construction involves building the tables in local memory, which are
then copied into guest memory. While actually used parts of the local
memory are filled in correctly, excess space that is being allocated is
left with its prior contents. |
