CVE-2026-89958

Kernel crash via unchecked KVM pointer dereference

Published Sep 16, 2026 · Updated Sep 16, 2026

NULL pointer dereference in the Linux s390 vfio-ap driver allows attackers to crash the host during AP configuration changes. The configuration-change and scan-completion callback paths lock matrix_mdev->kvm->lock without first checking whether matrix_mdev->kvm is NULL. The fault requires an vfio-ap mediated device whose KVM pointer was never set and a host AP configuration change that invokes either callback.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

NULL pointer dereference in the Linux s390 vfio-ap driver allows attackers to crash the host during AP configuration changes. The configuration-change and scan-completion callback paths lock matrix_mdev->kvm->lock without first checking whether matrix_mdev->kvm is NULL. The fault requires an vfio-ap mediated device whose KVM pointer was never set and a host AP configuration change that invokes either callback.

The record

CVE
CVE-2026-89958
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=6.0
  2. Affected versionversion=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <178ea7a1c2c3c0c01d14b8f60aa35f1e0cdc6b78
  3. Affected versionversion=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <334b435b951353f934d5110c4630e0cb58d2f9a7
  4. Affected versionversion=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <4f7e869d0db24ae07b4c888fd3bc21554eef775d
  5. Affected versionversion=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <5e932abfcce6189d067fffb0eb8214443bc04374
  6. Affected versionversion=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <d50346801b4f144e42b49cd4f1496010498ab114

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=6.0; version=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <178ea7a1c2c3c0c01d14b8f60aa35f1e0cdc6b78; version=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <334b435b951353f934d5110c4630e0cb58d2f9a7; version=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <4f7e869d0db24ae07b4c888fd3bc21554eef775d; version=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <5e932abfcce6189d067fffb0eb8214443bc04374; version=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <d50346801b4f144e42b49cd4f1496010498ab114

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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