CVE-2026-74259

Local system crash via CIFS unmount cleanup race

Published Aug 15, 2026 · Updated Aug 15, 2026

NULL pointer dereference in the Linux kernel CIFS client allows local users to crash the system by unmounting a share during file cleanup. CIFS can queue file objects on fileinfo_put_wq during unmount, then cifsFileInfo_put_final calls dput after superblock teardown and reaches list_lru_add with invalid state. Triggering the race requires privileges to mount and unmount a CIFS share while queued file cleanup remains pending; the demonstrated consequence is a kernel crash.

CVSS severity8.4
High
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the Linux kernel CIFS client allows local users to crash the system by unmounting a share during file cleanup. CIFS can queue file objects on fileinfo_put_wq during unmount, then cifsFileInfo_put_final calls dput after superblock teardown and reaches list_lru_add with invalid state. Triggering the race requires privileges to mount and unmount a CIFS share while queued file cleanup remains pending; the demonstrated consequence is a kernel crash.

The record

CVE
CVE-2026-74259
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 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 <4465ebe67d89345954bb3622b25dd13e06f9d367
  2. Affected versionversion=0e4b8faaaebe3137bec5723ef2b3cb0437fb38fd <3baedc9b2f53e6a6ac57b16fdff0f9b954d9ca71
  3. Affected versionversion=30afc6ea72cc6cf7c8d579e79b64232801c38d08
  4. Affected versionversion=340cea84f691c5206561bb2e0147158fe02070be <6d9a4aaaa8b2612b5ef9d581e2f286a458b71ee1
  5. Affected versionversion=340cea84f691c5206561bb2e0147158fe02070be <7839f1817a0cb6c4ed5cfe25d04845c43380a129
  6. Affected versionversion=6.1.167 <6.1.178
  7. Affected versionversion=6.12.78 <6.12.97
  8. Affected versionversion=6.18.20 <6.18.40
  9. Affected versionversion=6.19.10 <6.20
  10. Affected versionversion=6.6.130 <6.6.145
  11. Affected versionversion=7.0
  12. Affected versionversion=708c276f516d27beaded7f372ac8111cee43926c <55fb9581986141659002264fdc75cef307811eb8
  13. Affected versionversion=f655467a9973f964b267871e5fef533ad5014494 <21303c4a2b7275e626c6b67de0f45f2d5b9bb3e7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0629a1a187e424373364d681b42b101894bdb548 <4465ebe67d89345954bb3622b25dd13e06f9d367; version=0e4b8faaaebe3137bec5723ef2b3cb0437fb38fd <3baedc9b2f53e6a6ac57b16fdff0f9b954d9ca71; version=30afc6ea72cc6cf7c8d579e79b64232801c38d08; version=340cea84f691c5206561bb2e0147158fe02070be <6d9a4aaaa8b2612b5ef9d581e2f286a458b71ee1; version=340cea84f691c5206561bb2e0147158fe02070be <7839f1817a0cb6c4ed5cfe25d04845c43380a129; version=6.1.167 <6.1.178; version=6.12.78 <6.12.97; version=6.18.20 <6.18.40; version=6.19.10 <6.20; version=6.6.130 <6.6.145; version=7.0; version=708c276f516d27beaded7f372ac8111cee43926c <55fb9581986141659002264fdc75cef307811eb8; version=f655467a9973f964b267871e5fef533ad5014494 <21303c4a2b7275e626c6b67de0f45f2d5b9bb3e7

Published CVSS scores

4.1Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
8.4cve.orgCVSS:3.1/AV:L/AC:L/PR:N/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
T1499Endpoint Denial of Service

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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