CVE-2026-31446

Memory corruption via ext4 unmount race

Published Apr 22, 2026 · Updated Apr 22, 2026

Use-after-free in the ext4 filesystem in Linux Kernel allows local users to corrupt kernel memory during a race with filesystem unmount. The update_super_work path calls sysfs_notify() after ext4_unregister_sysfs() deletes the kobject, dereferencing its freed kernfs_node. The published assessment requires local access and user interaction; no specific post-corruption exploit outcome has been published.

CVSS severity7.8
High
EPSS probability0.14%
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 ext4 filesystem in Linux Kernel allows local users to corrupt kernel memory during a race with filesystem unmount. The update_super_work path calls sysfs_notify() after ext4_unregister_sysfs() deletes the kobject, dereferencing its freed kernfs_node. The published assessment requires local access and user interaction; no specific post-corruption exploit outcome has been published.

The record

CVE
CVE-2026-31446
Published
Apr 22, 2026
Updated
Apr 22, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=5.18
  2. Affected versionversion=52c3a04f9ec2a16a4204d6274db338cb8d5b2d74 <c8fe17a1b308c3d8c703ebfb049b325f844342c3
  3. Affected versionversion=585ef03c9e79672781f954daae730dfe24bf3a46
  4. Affected versionversion=afe490e48d47df1b3f64012835c1bc2f075a8c8b
  5. Affected versionversion=b98535d091795a79336f520b0708457aacf55c67 <034053378dd81837fd6c7a43b37ee2e58d4f0b4e
  6. Affected versionversion=b98535d091795a79336f520b0708457aacf55c67 <08b10e6f37fc533a759e9833af0692242e8b3f93
  7. Affected versionversion=b98535d091795a79336f520b0708457aacf55c67 <9449f99ba04f5dd1c8423ad8a90b3651d7240d1d
  8. Affected versionversion=b98535d091795a79336f520b0708457aacf55c67 <c4d829737329f2290dd41e290b7d75effdb2a7ff
  9. Affected versionversion=b98535d091795a79336f520b0708457aacf55c67 <c97e282f7bfd0c3554c63d289964a5ca6a1d2ffe
  10. Affected versionversion=b98535d091795a79336f520b0708457aacf55c67 <d15e4b0a418537aafa56b2cb80d44add83e83697

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.18; version=52c3a04f9ec2a16a4204d6274db338cb8d5b2d74 <c8fe17a1b308c3d8c703ebfb049b325f844342c3; version=585ef03c9e79672781f954daae730dfe24bf3a46; version=afe490e48d47df1b3f64012835c1bc2f075a8c8b; version=b98535d091795a79336f520b0708457aacf55c67 <034053378dd81837fd6c7a43b37ee2e58d4f0b4e; version=b98535d091795a79336f520b0708457aacf55c67 <08b10e6f37fc533a759e9833af0692242e8b3f93; version=b98535d091795a79336f520b0708457aacf55c67 <9449f99ba04f5dd1c8423ad8a90b3651d7240d1d; version=b98535d091795a79336f520b0708457aacf55c67 <c4d829737329f2290dd41e290b7d75effdb2a7ff; version=b98535d091795a79336f520b0708457aacf55c67 <c97e282f7bfd0c3554c63d289964a5ca6a1d2ffe; version=b98535d091795a79336f520b0708457aacf55c67 <d15e4b0a418537aafa56b2cb80d44add83e83697

Published CVSS scores

7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:N/UI:R/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free

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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