CVE-2026-89769

Use-after-free via leaked IRQ registration

Published Sep 11, 2026 · Updated Sep 11, 2026

Use-after-free in the NXP PIT clocksource driver in Linux 6.18 allows attackers to trigger stale IRQ handler access after initialization fails. The cpuhp_setup_state error path skips pit_clockevent_per_cpu_exit after request_irq succeeds, then frees pit while its address remains registered as the IRQ dev_id. Reachability requires CPU hotplug state setup to fail at that point and the retained IRQ to fire afterward, exposing the freed object to interrupt handling.

CVSS severityUnavailable
Unscored
EPSS probability0.12%
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 the NXP PIT clocksource driver in Linux 6.18 allows attackers to trigger stale IRQ handler access after initialization fails. The cpuhp_setup_state error path skips pit_clockevent_per_cpu_exit after request_irq succeeds, then frees pit while its address remains registered as the IRQ dev_id. Reachability requires CPU hotplug state setup to fail at that point and the retained IRQ to fire afterward, exposing the freed object to interrupt handling.

The record

CVE
CVE-2026-89769
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 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=6.18
  2. Affected versionversion=bee33f22d7c30626e711b4900e3f460b6e0e104f <05520e035f8332c8e33f3011b5ca016fde61793d
  3. Affected versionversion=bee33f22d7c30626e711b4900e3f460b6e0e104f <cdcd861123248e871c2ec2be968b0a1b2a5a34b0
  4. Affected versionversion=bee33f22d7c30626e711b4900e3f460b6e0e104f <d53c29a89a15e56a1797f3ef249955e544782e04

What conditions does exploitation require?

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

What is affected?

The Linux Kernel Organization · Linuxversion=6.18; version=bee33f22d7c30626e711b4900e3f460b6e0e104f <05520e035f8332c8e33f3011b5ca016fde61793d; version=bee33f22d7c30626e711b4900e3f460b6e0e104f <cdcd861123248e871c2ec2be968b0a1b2a5a34b0; version=bee33f22d7c30626e711b4900e3f460b6e0e104f <d53c29a89a15e56a1797f3ef249955e544782e04

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

No sourced classifications are available.

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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