CVE-2026-89960

Host use-after-free via stale PQAP hook

Published Sep 16, 2026 · Updated Sep 16, 2026

Use-after-free in Linux allows guest OS users to trigger a host-kernel use-after-free via PQAP after a failed VFIO AP assignment. A failed second mediated-device attachment overwrites kvm->arch.crypto.pqap_hook before conflict checks and returns without restoring it; closing that device leaves the hook dangling. Reaching the flaw requires an s390 KVM host with vfio_ap mediated devices and IBM Z Adjunct Processor hardware.

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

Use-after-free in Linux allows guest OS users to trigger a host-kernel use-after-free via PQAP after a failed VFIO AP assignment. A failed second mediated-device attachment overwrites kvm->arch.crypto.pqap_hook before conflict checks and returns without restoring it; closing that device leaves the hook dangling. Reaching the flaw requires an s390 KVM host with vfio_ap mediated devices and IBM Z Adjunct Processor hardware.

The record

CVE
CVE-2026-89960
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
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=5.15
  2. Affected versionversion=86956e70761b3292156d668e87126844334dd71b <13bfc94eef389bd664ffc67b00184919902c938a
  3. Affected versionversion=86956e70761b3292156d668e87126844334dd71b <4400270ec0348d05dc0439d8f0130853ce7f9e20
  4. Affected versionversion=86956e70761b3292156d668e87126844334dd71b <6a180adafc2a8a5fbe815985c71b2201e93ab5e1
  5. Affected versionversion=86956e70761b3292156d668e87126844334dd71b <eb6cc898501a004c0fa8aab951351d9c959b91cc
  6. Affected versionversion=86956e70761b3292156d668e87126844334dd71b <fc069d00a0dbef40042fd681554d48dcd5a1d524

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.15; version=86956e70761b3292156d668e87126844334dd71b <13bfc94eef389bd664ffc67b00184919902c938a; version=86956e70761b3292156d668e87126844334dd71b <4400270ec0348d05dc0439d8f0130853ce7f9e20; version=86956e70761b3292156d668e87126844334dd71b <6a180adafc2a8a5fbe815985c71b2201e93ab5e1; version=86956e70761b3292156d668e87126844334dd71b <eb6cc898501a004c0fa8aab951351d9c959b91cc; version=86956e70761b3292156d668e87126844334dd71b <fc069d00a0dbef40042fd681554d48dcd5a1d524

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 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

T1499.004Application or System Exploitation

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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