[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.

The remote Fedora 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-9b1af4c793 advisory.

    update to xen 4.20.4     includes security fixes     x86 shadow paging is deprecated [XSA-495, CVE-2026-42493]     vIRQ event channel binding may break Xenstore [XSA-496, CVE-2026-42492]     buffer overruns in libfsimage iso9660 handling [XSA-497, CVE-2026-42494,     CVE-2026-42495, CVE-2026-62423, CVE-2026-62424, CVE-2026-62425]     sysctl and platform-op locks open to abuse [XSA-499, CVE-2026-62426,     CVE-2026-62427]     grant-table: type confusion in grant-copy [XSA-500, CVE-2026-62428]     grant-table: version change racing with other operations [XSA-501,     CVE-2026-62435, CVE-2026-62436]     vNUMA domain cleanup may race other operations [XSA-502, CVE-2026-62429]     x86: Out-of-bounds read in vRTC emulation [XSA-503, CVE-2026-62430]     Viridian STIMER division by zero [XSA-504, CVE-2026-62431]     evtchn: Race between FIFO expand and reset [XSA-505, CVE-2026-62432]     correct buffer checks for DM_OP hypercalls [XSA-506, CVE-2026-62433]     PoD: Don't try to reclaim special pages [XSA-507, CVE-2026-62434]     pygrub is only supported in de-privileged mode [XSA-508]     x86 HVM I/O port list traversal [XSA-491, CVE-2026-42487]     domctl lock open to abuse [XSA-492, CVE-2026-42489, CVE-2026-42490]     Arm: Completion of memory accesses not guaranteed by completion of a TLBI     [XSA-493, CVE-2025-10263]     x86: mismatched mapcache metadata [XSA-494, CVE-2026-42488]

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6424 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6424-1                   security@debian.org     https://www.debian.org/security/                       Moritz Muehlenhoff     August 09, 2026                       https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : xen     CVE ID         : CVE-2025-10263 CVE-2025-54505 CVE-2025-54518 CVE-2026-23554                      CVE-2026-23555 CVE-2026-23556 CVE-2026-23557 CVE-2026-23558                      CVE-2026-42487 CVE-2026-42488 CVE-2026-42489 CVE-2026-42490                      CVE-2026-42493 CVE-2026-42494 CVE-2026-42495 CVE-2026-62423                      CVE-2026-62424 CVE-2026-62425 CVE-2026-62426 CVE-2026-62427                      CVE-2026-62428 CVE-2026-62429 CVE-2026-62430 CVE-2026-62431                      CVE-2026-62432 CVE-2026-62433 CVE-2026-62434 CVE-2026-62435                      CVE-2026-62436

    Multiple vulnerabilities have been discovered in the Xen hypervisor,     which could result in privilege escalation, information disclosure or     denial of service.

    For the stable distribution (trixie), these problems have been fixed in     version 4.20.3+127-gc42374a105-0+deb13u1.

    We recommend that you upgrade your xen packages.

    For the detailed security status of xen please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/xen

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES12 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:2668-1 advisory.

    - CVE-2026-42487: xen: x86 HVM I/O port list traversal (XSA-491) (bsc#1266952).
    - CVE-2026-42488: xen: x86: mismatched mapcache metadata (XSA-494) (bsc#1266955).
    - CVE-2026-42489,CVE-2026-42490: xen: domctl lock open to abuse (XSA-492) (bsc#1266953).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:2613-1 advisory.

    This update for xen fixes the following issues

    - CVE-2025-54518: AMD-SN-7052: CPU OP Cache Corruption (bsc#1264066).
    - CVE-2026-42487: x86 HVM I/O port list traversal (bsc#1266952).
    - CVE-2026-42488: x86: mismatched mapcache metadata (bsc#1266955).
    - CVE-2026-42489,CVE-2026-42490: domctl lock open to abuse (bsc#1266953).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-24b84f97af advisory.

    x86 HVM I/O port list traversal [XSA-491, CVE-2026-42487]     domctl lock open to abuse [XSA-492, CVE-2026-42489, CVE-2026-42490]     Arm: Completion of memory accesses not guaranteed by completion of a TLBI     [XSA-493, CVE-2025-10263]     x86: mismatched mapcache metadata [XSA-494, CVE-2026-42488]

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:2329-1 advisory.

    - CVE-2026-42487: x86 HVM I/O port list traversal (bsc#1266952).
    - CVE-2026-42488: x86: mismatched mapcache metadata (bsc#1266955).
    - CVE-2026-42489,CVE-2026-42490: domctl lock open to abuse (bsc#1266953).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:2364-1 advisory.

    - CVE-2026-42487: x86 HVM I/O port list traversal (bsc#1266952).
    - CVE-2026-42488: x86: mismatched mapcache metadata (bsc#1266955).
    - CVE-2026-42489,CVE-2026-42490: domctl lock open to abuse (bsc#1266953).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:2328-1 advisory.

    - CVE-2026-42487: x86 HVM I/O port list traversal (bsc#1266952).
    - CVE-2026-42488: x86: mismatched mapcache metadata (bsc#1266955).
    - CVE-2026-42489,CVE-2026-42490: domctl lock open to abuse (bsc#1266953).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

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. A less privileged entity may stall an equally or more privileged entity, potentially leading to a Denial of Service (DoS) of up to the entire host.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - Arm C1-Ultra, C1-Premium, Neoverse V3 & V3AE, Neoverse V2, Neoverse V1, Neoverse-N2, Neoverse-N1,
    Cortex-X925, Cortex-X4, Cortex-X3, Cortex-X2, Cortex-X1 & X1C, Cortex-A710, Cortex-A78, A78AE & A78C,
    Cortex-A77, Cortex-A76 & A76A may allow writes to resources owned by a higher exception level.
    (CVE-2025-10263)

  - 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. (CVE-2026-42487)

  - 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. (CVE-2026-42488)

  - [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. (CVE-2026-42489,
    CVE-2026-42490)

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - [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. (CVE-2026-42489)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
334454	Fedora 43 : xen (2026-9b1af4c793)	Nessus	Fedora Local Security Checks	Local	high
333555	Debian dsa-6424 : libxen-dev - security update	Nessus	Debian Local Security Checks	Local	critical
323887	SUSE SLES12: xen / xen-devel / xen-doc-html / xen-libs / xen-libs-32bit / etc (SUSE-SU-2026:2668-1)	Nessus	SuSE Local Security Checks	Local	high
322888	SUSE SLES15: xen / xen-devel / xen-libs / xen-tools / xen-tools-domU / etc (SUSE-SU-2026:2613-1)	Nessus	SuSE Local Security Checks	Local	high
321439	Fedora 44 : xen (2026-24b84f97af)	Nessus	Fedora Local Security Checks	Local	high
321054	SUSE SLES15 Security Update : xen (SUSE-SU-2026:2329-1)	Nessus	SuSE Local Security Checks	Local	high
321030	SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2026:2364-1)	Nessus	SuSE Local Security Checks	Local	high
321022	SUSE SLES15 Security Update : xen (SUSE-SU-2026:2328-1)	Nessus	SuSE Local Security Checks	Local	high
320869	Xen: domctl Lock Open to Abuse (XSA-492)	Nessus	Misc.	Local	medium
442839	Alpine: multiple xen packages: security update to 4.20.3-r4	Tenable Cloud Security	Alpine Linux Local Security Checks	Local	high
442839	Alpine: multiple xen packages: security update to 4.20.3-r4	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	Local	high
320151	Linux Distros Unpatched Vulnerability : CVE-2026-42489	Nessus	Misc.	Local	medium

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