CVE-2026-89955

Local denial of service via queue-probe race

Published Sep 16, 2026 · Updated Sep 16, 2026

A race in Linux 6.0 s390 vfio-ap allows local users to trigger a kernel NULL-pointer dereference by reading an AP queue status file. During queue probing, status_show can obtain unset driver data and pass NULL to vfio_ap_mdev_for_queue, which dereferences q->apqn. The path requires IBM Z AP hardware, the vfio_ap driver, and a status read before queue driver data is installed; the kernel fault can interrupt the host.

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

A race in Linux 6.0 s390 vfio-ap allows local users to trigger a kernel NULL-pointer dereference by reading an AP queue status file. During queue probing, status_show can obtain unset driver data and pass NULL to vfio_ap_mdev_for_queue, which dereferences q->apqn. The path requires IBM Z AP hardware, the vfio_ap driver, and a status read before queue driver data is installed; the kernel fault can interrupt the host.

The record

CVE
CVE-2026-89955
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=260f3ea141382386e97611e7c2029bc013088ab1 <31fa0a8a3c337ed2d200166d6926ab23c14f8b2e
  2. Affected versionversion=260f3ea141382386e97611e7c2029bc013088ab1 <69632952aca04caa71e49953b6949fc04e788e67
  3. Affected versionversion=260f3ea141382386e97611e7c2029bc013088ab1 <7db2511fc601ca3a6e3fb1bdce02261c3c3167c3
  4. Affected versionversion=260f3ea141382386e97611e7c2029bc013088ab1 <dd6f4ef6f8a37412909ad787c837332fb070159c
  5. Affected versionversion=260f3ea141382386e97611e7c2029bc013088ab1 <e102ce0f4af99dff769a4b1b4daa4cc6bd5ad2d9
  6. Affected versionversion=6.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=260f3ea141382386e97611e7c2029bc013088ab1 <31fa0a8a3c337ed2d200166d6926ab23c14f8b2e; version=260f3ea141382386e97611e7c2029bc013088ab1 <69632952aca04caa71e49953b6949fc04e788e67; version=260f3ea141382386e97611e7c2029bc013088ab1 <7db2511fc601ca3a6e3fb1bdce02261c3c3167c3; version=260f3ea141382386e97611e7c2029bc013088ab1 <dd6f4ef6f8a37412909ad787c837332fb070159c; version=260f3ea141382386e97611e7c2029bc013088ab1 <e102ce0f4af99dff769a4b1b4daa4cc6bd5ad2d9; version=6.0

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

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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