CVE-2026-89958: Software Security Vulnerability Vulnerability

UNKNOWN
Advisory Identifier: GHSA-hgjh-2rgq-2xcv
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Advisory Summary

CVE-2026-89958 is a security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2026-89958 at a Glance

CVE Identifier CVE-2026-89958
GHSA Identifier GHSA-hgjh-2rgq-2xcv
Severity N/A
CVSS v3.1 Base Score N/A
CWE Classification General Security Weakness
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-89958

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-89958, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under General Security Weakness. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

In the Linux kernel, the following vulnerability has been resolved: s390/vfio-ap: Fix dereference matrix_mdev->kvm without checking for NULL The ap_driver structure has two fields which are function pointers to callbacks: * .on_config_changed: called at the start of the AP bus scan function to notify the device driver that the host AP configuration has changed and the associated AP devices will be added or removed accordingly. This gives the implementor a chance to evaluate the configuration changes and respond to them before the associated devices are added or removed. * .on_scan_complete: Called at the end of the AP bus scan function to notify the device driver that the host AP configuration has changed and the AP devices have been added or removed accordingly. This gives the implementor the opportunity to respond to the changes after the associated devices are added or removed. These two callbacks are implemented in the vfio_ap device driver via the vfio_ap_on_cfg_changed and vfio_ap_on_scan_complete functions respectively. Within the call stack of these two callback functions the matrix_mdev->kvm->lock mutex is taken without checking whether matrix_mdev->kvm is NULL or not. If matrix_mdev->kvm has never been set, trying to take the lock will trigger a NULL pointer dereference. This patch adds checks for matrix_mdev->kvm == NULL before taking the matrix_mdev->kvm->lock mutex. Note that the matrix_mdev->kvm->lock mutex taken in the vfio_ap_mdev_hot_plug_config function is moved to the calling function along with the matrix_dev->mdevs_lock which is needed there to access the fields of the matrix_mdev. It makes little sense to make the change the check for matrix_mdev->kvm there before taking the kvm->lock mutex only to have to move it out via another patch, so it is done in this patch. It is important to make note of the following: 1. The matrix_dev->guests_lock is acquired at the start of both callback functions. This ensures that matrix_mdev will not be removed via the vfio_ap_mdev_remove function because it too takes matrix_dev_guests_lock before removing the object; so, matrix_mdev will be available for the duration of the callback functions. 2. The matrix_dev->mdevs_lock mutex must be taken in order to access fields within the matrix_mdev structure 3. matrix_mdev->kvm->lock mutex must be taken before the matrix_dev->mdevs_lock to prevent a lockdep splat. 4: The kvm->lock must be held while plugging the guest's AP configuration into its SIE state description via the vfio_ap_mdev_update_guest_apcb function. 5. The vfio_ap_mdev_update_guest_apcb checks matrix_mdev->kvm to verify it is not NULL before doing the hot plug of the guest's AP configuration.

References

NVD — CVE-2026-89958 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89958
git.kernel.org/stable/c/178ea7a1c2... WEB
https://git.kernel.org/stable/c/178ea7a1c2c3c0c01d14b8f60aa35f1e0cdc6b78
git.kernel.org/stable/c/334b435b95... WEB
https://git.kernel.org/stable/c/334b435b951353f934d5110c4630e0cb58d2f9a7
git.kernel.org/stable/c/4f7e869d0d... WEB
https://git.kernel.org/stable/c/4f7e869d0db24ae07b4c888fd3bc21554eef775d
git.kernel.org/stable/c/5e932abfcc... WEB
https://git.kernel.org/stable/c/5e932abfcce6189d067fffb0eb8214443bc04374
git.kernel.org/stable/c/d50346801b... WEB
https://git.kernel.org/stable/c/d50346801b4f144e42b49cd4f1496010498ab114

Frequently Asked Questions

What is CVE-2026-89958?
CVE-2026-89958 is a security vulnerability in Software classified as a security vulnerability vulnerability under General Security Weakness.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-89958?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-89958?
CVE-2026-89958 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-89958?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hgjh-2rgq-2xcv",
  "modified" : "2026-09-16T12:30:43Z",
  "published" : "2026-09-16T12:30:43Z",
  "aliases" : [ "CVE-2026-89958" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio-ap: Fix dereference matrix_mdev->kvm without checking for NULL\n\nThe ap_driver structure has two fields which are function pointers to\ncallbacks:\n\n* .on_config_changed: called at the start of the AP bus scan function to\n                      notify the device driver that the host AP\n                      configuration has changed and the associated AP\n                      devices will be added or removed accordingly. This\n                      gives the implementor a chance to evaluate the\n                      configuration changes and respond to them before\n                      the associated devices are added or removed.\n\n* .on_scan_complete:  Called at the end of the AP bus scan function to\n                      notify the device driver that the host AP\n                      configuration has changed and the AP devices have\n                      been added or removed accordingly. This gives the\n                      implementor the opportunity to respond to the\n                      changes after the associated devices are added or\n                      removed.\n\nThese two callbacks are implemented in the vfio_ap device driver via the\nvfio_ap_on_cfg_changed and vfio_ap_on_scan_complete functions respectively.\n\nWithin the call stack of these two callback functions the\nmatrix_mdev->kvm->lock mutex is taken without checking whether\nmatrix_mdev->kvm is NULL or not. If matrix_mdev->kvm has never been set,\ntrying to take the lock will trigger a NULL pointer dereference. This patch\nadds checks for matrix_mdev->kvm == NULL before taking the\nmatrix_mdev->kvm->lock mutex.\n\nNote that the matrix_mdev->kvm->lock mutex taken in the\nvfio_ap_mdev_hot_plug_config function is moved to the calling function\nalong with the matrix_dev->mdevs_lock which is needed there to access\nthe fields of the matrix_mdev. It makes little sense to make the change\nthe check for matrix_mdev->kvm there before taking the kvm->lock\nmutex only to have to move it out via another patch, so it is done in\nthis patch.\n\nIt is important to make note of the following:\n1. The matrix_dev->guests_lock is acquired at the start of both callback\n   functions. This ensures that matrix_mdev will not be removed via the\n   vfio_ap_mdev_remove function because it too takes matrix_dev_guests_lock\n   before removing the object; so, matrix_mdev will be available for the\n   duration of the callback functions.\n\n2. The matrix_dev->mdevs_lock mutex must be taken in order to access\n   fields within the matrix_mdev structure\n\n3. matrix_mdev->kvm->lock mutex must be taken before the\n   matrix_dev->mdevs_lock to prevent a lockdep splat.\n\n4: The kvm->lock must be held while plugging the guest's AP configuration\n   into its SIE state description via the vfio_ap_mdev_update_guest_apcb\n   function.\n\n5. The vfio_ap_mdev_update_guest_apcb checks matrix_mdev->kvm to verify it\n   is not NULL before doing the hot plug of the guest's AP configuration.",
  "severity" : [ ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-89958"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/178ea7a1c2c3c0c01d14b8f60aa35f1e0cdc6b78"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/334b435b951353f934d5110c4630e0cb58d2f9a7"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/4f7e869d0db24ae07b4c888fd3bc21554eef775d"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/5e932abfcce6189d067fffb0eb8214443bc04374"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/d50346801b4f144e42b49cd4f1496010498ab114"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : null,
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-16T11:17:06Z"
  }
}