Upstream information

CVE-2026-31788 at MITRE

Description

In the Linux kernel, the following vulnerability has been resolved:

xen/privcmd: restrict usage in unprivileged domU

The Xen privcmd driver allows to issue arbitrary hypercalls from
user space processes. This is normally no problem, as access is
usually limited to root and the hypervisor will deny any hypercalls
affecting other domains.

In case the guest is booted using secure boot, however, the privcmd
driver would be enabling a root user process to modify e.g. kernel
memory contents, thus breaking the secure boot feature.

The only known case where an unprivileged domU is really needing to
use the privcmd driver is the case when it is acting as the device
model for another guest. In this case all hypercalls issued via the
privcmd driver will target that other guest.

Fortunately the privcmd driver can already be locked down to allow
only hypercalls targeting a specific domain, but this mode can be
activated from user land only today.

The target domain can be obtained from Xenstore, so when not running
in dom0 restrict the privcmd driver to that target domain from the
beginning, resolving the potential problem of breaking secure boot.

This is XSA-482

---
V2:
- defer reading from Xenstore if Xenstore isn't ready yet (Jan Beulich)
- wait in open() if target domain isn't known yet
- issue message in case no target domain found (Jan Beulich)

SUSE information

Overall state of this security issue: Resolved

This issue is currently rated as having moderate severity.

Note from the SUSE Security Team on the xen package

This issue likely only affects the XEN hypervisor itself, unless otherwise stated. The userland utilities in -tools and libraries in -libs are shipped together with the xen hypervisor as they are built from one source and do not contain hypervisor specific fixes.

SUSE Bugzilla entry: 1259707 [NEW]

No SUSE Security Announcements cross referenced.


Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products under general support and receiving all security fixes.
SUSE Linux Enterprise Desktop 15 SP7 xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP7 xen Not affected
SUSE Linux Enterprise Micro 5.2 xen Not affected
SUSE Linux Enterprise Micro 5.3 xen Not affected
SUSE Linux Enterprise Micro 5.4 xen Not affected
SUSE Linux Enterprise Micro 5.5 xen Not affected
SUSE Linux Enterprise Module for Basesystem 15 SP7 xen Not affected
SUSE Linux Enterprise Module for Server Applications 15 SP7 xen Not affected
SUSE Linux Enterprise Server 15 SP7 xen Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP7 xen Not affected
openSUSE Leap 15.6 xen Not affected
Products under Long Term Service Pack support and receiving important and critical security fixes.
SUSE Linux Enterprise High Performance Computing 15 SP4 xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP5 xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS xen Not affected
SUSE Linux Enterprise Module for Basesystem 15 SP4 xen Not affected
SUSE Linux Enterprise Module for Basesystem 15 SP5 xen Not affected
SUSE Linux Enterprise Module for Basesystem 15 SP6 xen Not affected
SUSE Linux Enterprise Module for Server Applications 15 SP4 xen Not affected
SUSE Linux Enterprise Module for Server Applications 15 SP5 xen Not affected
SUSE Linux Enterprise Module for Server Applications 15 SP6 xen Not affected
SUSE Linux Enterprise Server 12 SP5 xen Not affected
SUSE Linux Enterprise Server 12 SP5-LTSS xen Not affected
SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security xen Not affected
SUSE Linux Enterprise Server 15 SP4 xen Not affected
SUSE Linux Enterprise Server 15 SP4-LTSS xen Not affected
SUSE Linux Enterprise Server 15 SP5 xen Not affected
SUSE Linux Enterprise Server 15 SP5-LTSS xen Not affected
SUSE Linux Enterprise Server 15 SP6 xen Not affected
SUSE Linux Enterprise Server 15 SP6-LTSS xen Not affected
SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 xen Not affected
SUSE Linux Enterprise Server for SAP Applications 12 SP5 xen Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP6 xen Not affected
SUSE Manager Proxy 4.3 xen Not affected
SUSE Manager Proxy LTS 4.3 xen Not affected
SUSE Manager Retail Branch Server 4.3 xen Not affected
SUSE Manager Retail Branch Server LTS 4.3 xen Not affected
SUSE Manager Server 4.3 xen Not affected
SUSE Manager Server LTS 4.3 xen Not affected
Products past their end of life and not receiving proactive updates anymore.
HPE Helion OpenStack 8 xen Not affected
SUSE CaaS Platform 3.0 xen Not affected
SUSE CaaS Platform 4.0 xen Not affected
SUSE Enterprise Storage 6 xen Not affected
SUSE Enterprise Storage 7 xen Not affected
SUSE Enterprise Storage 7.1 xen Not affected
SUSE Linux Enterprise Desktop 12 SP2 xen Not affected
SUSE Linux Enterprise Desktop 12 SP3 xen Not affected
SUSE Linux Enterprise Desktop 12 SP4 xen Not affected
SUSE Linux Enterprise Desktop 15 SP1 xen Not affected
SUSE Linux Enterprise Desktop 15 SP2 xen Not affected
SUSE Linux Enterprise Desktop 15 SP3 xen Not affected
SUSE Linux Enterprise Desktop 15 SP4 xen Not affected
SUSE Linux Enterprise Desktop 15 SP5 xen Not affected
SUSE Linux Enterprise Desktop 15 SP6 xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP1 xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP2 xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP3 xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS xen Not affected
SUSE Linux Enterprise High Performance Computing 15 SP6 xen Not affected
SUSE Linux Enterprise Micro 5.0 xen Not affected
SUSE Linux Enterprise Micro 5.1 xen Not affected
SUSE Linux Enterprise Module for Basesystem 15 SP1 xen Not affected
SUSE Linux Enterprise Module for Basesystem 15 SP2 xen Not affected
SUSE Linux Enterprise Module for Basesystem 15 SP3 xen Not affected
SUSE Linux Enterprise Module for Server Applications 15 SP1 xen Not affected
SUSE Linux Enterprise Module for Server Applications 15 SP2 xen Not affected
SUSE Linux Enterprise Module for Server Applications 15 SP3 xen Not affected
SUSE Linux Enterprise Point of Sale 12 SP2-CLIENT xen Not affected
SUSE Linux Enterprise Real Time 15 SP2 xen Not affected
SUSE Linux Enterprise Real Time 15 SP3 xen Not affected
SUSE Linux Enterprise Real Time 15 SP4 xen Not affected
SUSE Linux Enterprise Server 12 SP2 xen Not affected
SUSE Linux Enterprise Server 12 SP2-BCL xen Not affected
SUSE Linux Enterprise Server 12 SP2-ESPOS xen Not affected
SUSE Linux Enterprise Server 12 SP2-LTSS xen Not affected
SUSE Linux Enterprise Server 12 SP3 xen Not affected
SUSE Linux Enterprise Server 12 SP3-BCL xen Not affected
SUSE Linux Enterprise Server 12 SP3-ESPOS xen Not affected
SUSE Linux Enterprise Server 12 SP3-LTSS xen Not affected
SUSE Linux Enterprise Server 12 SP4 xen Not affected
SUSE Linux Enterprise Server 12 SP4-ESPOS xen Not affected
SUSE Linux Enterprise Server 12 SP4-LTSS xen Not affected
SUSE Linux Enterprise Server 15 SP1 xen Not affected
SUSE Linux Enterprise Server 15 SP1-BCL xen Not affected
SUSE Linux Enterprise Server 15 SP1-LTSS xen Not affected
SUSE Linux Enterprise Server 15 SP2 xen Not affected
SUSE Linux Enterprise Server 15 SP2-BCL xen Not affected
SUSE Linux Enterprise Server 15 SP2-LTSS xen Not affected
SUSE Linux Enterprise Server 15 SP3 xen Not affected
SUSE Linux Enterprise Server 15 SP3-BCL xen Not affected
SUSE Linux Enterprise Server 15 SP3-LTSS xen Not affected
SUSE Linux Enterprise Server for SAP Applications 12 SP2 xen Not affected
SUSE Linux Enterprise Server for SAP Applications 12 SP3 xen Not affected
SUSE Linux Enterprise Server for SAP Applications 12 SP4 xen Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP1 xen Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP2 xen Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP3 xen Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP4 xen Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP5 xen Not affected
SUSE Linux Enterprise Software Development Kit 12 SP2 xen Not affected
SUSE Linux Enterprise Software Development Kit 12 SP3 xen Not affected
SUSE Linux Enterprise Software Development Kit 12 SP4 xen Not affected
SUSE Linux Enterprise Software Development Kit 12 SP5 xen Not affected
SUSE Manager Proxy 4.0 xen Not affected
SUSE Manager Proxy 4.1 xen Not affected
SUSE Manager Proxy 4.2 xen Not affected
SUSE Manager Retail Branch Server 4.0 xen Not affected
SUSE Manager Retail Branch Server 4.1 xen Not affected
SUSE Manager Retail Branch Server 4.2 xen Not affected
SUSE Manager Server 4.0 xen Not affected
SUSE Manager Server 4.1 xen Not affected
SUSE Manager Server 4.2 xen Not affected
SUSE OpenStack Cloud 7 xen Not affected
SUSE OpenStack Cloud 8 xen Not affected
SUSE OpenStack Cloud 9 xen Not affected
SUSE OpenStack Cloud Crowbar 8 xen Not affected
SUSE OpenStack Cloud Crowbar 9 xen Not affected
openSUSE Leap 15.3 xen Not affected
openSUSE Leap 15.4 xen Not affected
openSUSE Leap 15.5 xen Not affected
openSUSE Leap Micro 5.2 xen Not affected
openSUSE Leap Micro 5.3 xen Not affected
openSUSE Leap Micro 5.4 xen Not affected
openSUSE Leap Micro 5.5 xen Not affected


SUSE Timeline for this CVE

CVE page created: Mon Mar 16 15:15:11 2026
CVE page last modified: Wed Mar 25 14:48:17 2026