CVE-2026-64108Public exploit

Kernel warning via deferred-close unmount race

Published Jul 19, 2026 · Updated Jul 19, 2026

Race condition in the CIFS client in affected Linux Kernel versions allows local users to trigger a busy-dentry warning during unmount. The close path queues cfile->deferred after dropping the file reference, so unmount can pass deferred-file cleanup while the worker still holds the dentry. Triggering requires local access to a mounted CIFS share and concurrent close and unmount activity; the reported consequence is a generic_shutdown_super warning.

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

Race condition in the CIFS client in affected Linux Kernel versions allows local users to trigger a busy-dentry warning during unmount. The close path queues cfile->deferred after dropping the file reference, so unmount can pass deferred-file cleanup while the worker still holds the dentry. Triggering requires local access to a mounted CIFS share and concurrent close and unmount activity; the reported consequence is a generic_shutdown_super warning.

The record

CVE
CVE-2026-64108
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 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=0629a1a187e424373364d681b42b101894bdb548 <bdc349a87f1fb02c18c4071858a06542bfea783d
  2. Affected versionversion=0e4b8faaaebe3137bec5723ef2b3cb0437fb38fd <f2deaa2f409a4598eaa10f2a93a676c0632af248
  3. Affected versionversion=30afc6ea72cc6cf7c8d579e79b64232801c38d08
  4. Affected versionversion=340cea84f691c5206561bb2e0147158fe02070be <c68337442f03953237a94577beb468ab2662a851
  5. Affected versionversion=340cea84f691c5206561bb2e0147158fe02070be <e1ffa6cf662383f95816eed1b623429d82675e75
  6. Affected versionversion=6.1.167 <6.1.175
  7. Affected versionversion=6.12.78 <6.12.92
  8. Affected versionversion=6.18.20 <6.18.34
  9. Affected versionversion=6.19.10 <6.20
  10. Affected versionversion=6.6.130 <6.6.142
  11. Affected versionversion=7.0
  12. Affected versionversion=708c276f516d27beaded7f372ac8111cee43926c <c7364cea52531534676b9f7dbc0a477c11f4c050
  13. Affected versionversion=f655467a9973f964b267871e5fef533ad5014494 <5e7d9d0805e58fa3760894e73115b7a74024fd07

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0629a1a187e424373364d681b42b101894bdb548 <bdc349a87f1fb02c18c4071858a06542bfea783d; version=0e4b8faaaebe3137bec5723ef2b3cb0437fb38fd <f2deaa2f409a4598eaa10f2a93a676c0632af248; version=30afc6ea72cc6cf7c8d579e79b64232801c38d08; version=340cea84f691c5206561bb2e0147158fe02070be <c68337442f03953237a94577beb468ab2662a851; version=340cea84f691c5206561bb2e0147158fe02070be <e1ffa6cf662383f95816eed1b623429d82675e75; version=6.1.167 <6.1.175; version=6.12.78 <6.12.92; version=6.18.20 <6.18.34; version=6.19.10 <6.20; version=6.6.130 <6.6.142; version=7.0; version=708c276f516d27beaded7f372ac8111cee43926c <c7364cea52531534676b9f7dbc0a477c11f4c050; version=f655467a9973f964b267871e5fef533ad5014494 <5e7d9d0805e58fa3760894e73115b7a74024fd07

Published CVSS scores

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 exploitPublished

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

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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