CVE-2026-23198

Host crash via stale IRQ bypass state

Published Feb 14, 2026 · Updated Feb 14, 2026

Use-after-free in Linux Kernel KVM allows local users with /dev/kvm access to crash the host through KVM_IRQFD deassignment. During irqfd deassignment, virt/kvm/eventfd.c overwrites the saved routing type before architecture cleanup, leaving IRQ bypass tied to freed irqfd state. Exploitation requires local access to a KVM VM file descriptor and /dev/kvm; AMD can hit a NULL dereference or list corruption, while Intel and arm64 can continue posting IRQs after deassignment.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux Kernel KVM allows local users with /dev/kvm access to crash the host through KVM_IRQFD deassignment. During irqfd deassignment, virt/kvm/eventfd.c overwrites the saved routing type before architecture cleanup, leaving IRQ bypass tied to freed irqfd state. Exploitation requires local access to a KVM VM file descriptor and /dev/kvm; AMD can hit a NULL dereference or list corruption, while Intel and arm64 can continue posting IRQs after deassignment.

The record

CVE
CVE-2026-23198
Published
Feb 14, 2026
Updated
Feb 14, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 14, 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=4.4
  2. Affected versionversion=f70c20aaf141adb715a2d750c55154073b02a9c3 <2284bc168b148a17b5ca3b37b3d95c411f18a08d
  3. Affected versionversion=f70c20aaf141adb715a2d750c55154073b02a9c3 <4385b2f2843549bfb932e0dcf76bf4b065543a3c
  4. Affected versionversion=f70c20aaf141adb715a2d750c55154073b02a9c3 <6d14ba1e144e796b5fc81044f08cfba9024ca195
  5. Affected versionversion=f70c20aaf141adb715a2d750c55154073b02a9c3 <959a063e7f12524bc1871ad1f519787967bbcd45
  6. Affected versionversion=f70c20aaf141adb715a2d750c55154073b02a9c3 <b4d37cdb77a0015f51fee083598fa227cc07aaf1
  7. Affected versionversion=f70c20aaf141adb715a2d750c55154073b02a9c3 <b61f9b2fcf181451d0a319889478cc53c001123e
  8. Affected versionversion=f70c20aaf141adb715a2d750c55154073b02a9c3 <ff48c9312d042bfbe826ca675e98acc6c623211c

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.4; version=f70c20aaf141adb715a2d750c55154073b02a9c3 <2284bc168b148a17b5ca3b37b3d95c411f18a08d; version=f70c20aaf141adb715a2d750c55154073b02a9c3 <4385b2f2843549bfb932e0dcf76bf4b065543a3c; version=f70c20aaf141adb715a2d750c55154073b02a9c3 <6d14ba1e144e796b5fc81044f08cfba9024ca195; version=f70c20aaf141adb715a2d750c55154073b02a9c3 <959a063e7f12524bc1871ad1f519787967bbcd45; version=f70c20aaf141adb715a2d750c55154073b02a9c3 <b4d37cdb77a0015f51fee083598fa227cc07aaf1; version=f70c20aaf141adb715a2d750c55154073b02a9c3 <b61f9b2fcf181451d0a319889478cc53c001123e; version=f70c20aaf141adb715a2d750c55154073b02a9c3 <ff48c9312d042bfbe826ca675e98acc6c623211c

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
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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