CVE-2026-90044

Kernel crash via stale AIO cancellation pointer

Published Sep 16, 2026 · Updated Sep 16, 2026

Use-after-free in Linux FunctionFS allows local users to crash the kernel through concurrent AIO cancellation after an I/O error. The ffs_epfile_write_iter() and ffs_epfile_read_iter() error paths free io_data while kiocb->private still points to it and cancellation remains armed. A local FunctionFS process must race sys_io_cancel() against a nonqueued ffs_epfile_io() failure; winning the race dereferences the freed object and interrupts the host.

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

What happened

Use-after-free in Linux FunctionFS allows local users to crash the kernel through concurrent AIO cancellation after an I/O error. The ffs_epfile_write_iter() and ffs_epfile_read_iter() error paths free io_data while kiocb->private still points to it and cancellation remains armed. A local FunctionFS process must race sys_io_cancel() against a nonqueued ffs_epfile_io() failure; winning the race dereferences the freed object and interrupts the host.

The record

CVE
CVE-2026-90044
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=4.0
  2. Affected versionversion=de2080d41b5d584205e408d72021f0f335a046fc <153b5ecd29ed055562400bc17c91df3fd869b0ce
  3. Affected versionversion=de2080d41b5d584205e408d72021f0f335a046fc <4a2fb2d12b87b43724230abb52a1440617c7b6cc
  4. Affected versionversion=de2080d41b5d584205e408d72021f0f335a046fc <e78dcb1f7ec271449c54984dc90c62a5ba272de7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.0; version=de2080d41b5d584205e408d72021f0f335a046fc <153b5ecd29ed055562400bc17c91df3fd869b0ce; version=de2080d41b5d584205e408d72021f0f335a046fc <4a2fb2d12b87b43724230abb52a1440617c7b6cc; version=de2080d41b5d584205e408d72021f0f335a046fc <e78dcb1f7ec271449c54984dc90c62a5ba272de7

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)
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.

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Technologies

Your stack

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Your stack

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