CVE-2026-90140

Kernel fault via stale module-unload callback

Published Sep 17, 2026 · Updated Sep 17, 2026

Use-after-free in Linux 6.8 CUSE allows local users to trigger a kernel page-fault Oops via /dev/cuse closure and module unload. In fs/fuse/cuse.c, cuse_exit() returns without waiting for deferred fuse_conn release callbacks, leaving cuse_fc_release() pointing into freed module text. Triggering the race requires module-unload privileges and a pending callback; address reuse produces undefined execution, not demonstrated attacker-controlled code execution.

CVSS severity4.1
Medium
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux 6.8 CUSE allows local users to trigger a kernel page-fault Oops via /dev/cuse closure and module unload. In fs/fuse/cuse.c, cuse_exit() returns without waiting for deferred fuse_conn release callbacks, leaving cuse_fc_release() pointing into freed module text. Triggering the race requires module-unload privileges and a pending callback; address reuse produces undefined execution, not demonstrated attacker-controlled code execution.

The record

CVE
CVE-2026-90140
Published
Sep 17, 2026
Updated
Sep 17, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=053fc4f755ad43cf35210677bcba798ccdc48d0c <389bd349ddbcf90dbd8a4f2a4ab6e552d53df134
  2. Affected versionversion=053fc4f755ad43cf35210677bcba798ccdc48d0c <4deb3edead0c0e172cc7349e8855d741d3c5e162
  3. Affected versionversion=053fc4f755ad43cf35210677bcba798ccdc48d0c <a1b46aee33d83f14ed62d7fdef1a91d3e0b732a9
  4. Affected versionversion=053fc4f755ad43cf35210677bcba798ccdc48d0c <c40f3f24839f8404325a2099e26c2a04786ae309
  5. Affected versionversion=5.15.166 <5.15.221
  6. Affected versionversion=535e9bd0e8f8d8cfdc29de7cdb902b5041427fe6 <ac5c499413385cea3e0220d6050408d50842891d
  7. Affected versionversion=6.1.107 <6.1.188
  8. Affected versionversion=6.6.48 <6.6.157
  9. Affected versionversion=6.8
  10. Affected versionversion=a8f650b93e55764ca9ff8e1ddebc151f57024086 <45ae914b2f6ea56fc2f1c017fdee4e995bcb4c0e
  11. Affected versionversion=bfbab62ca69f72bcd14ea30de1fb98f6080ad464 <7fe415e1cd8fa875be263670c0ab47109818abb6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=053fc4f755ad43cf35210677bcba798ccdc48d0c <389bd349ddbcf90dbd8a4f2a4ab6e552d53df134; version=053fc4f755ad43cf35210677bcba798ccdc48d0c <4deb3edead0c0e172cc7349e8855d741d3c5e162; version=053fc4f755ad43cf35210677bcba798ccdc48d0c <a1b46aee33d83f14ed62d7fdef1a91d3e0b732a9; version=053fc4f755ad43cf35210677bcba798ccdc48d0c <c40f3f24839f8404325a2099e26c2a04786ae309; version=5.15.166 <5.15.221; version=535e9bd0e8f8d8cfdc29de7cdb902b5041427fe6 <ac5c499413385cea3e0220d6050408d50842891d; version=6.1.107 <6.1.188; version=6.6.48 <6.6.157; version=6.8; version=a8f650b93e55764ca9ff8e1ddebc151f57024086 <45ae914b2f6ea56fc2f1c017fdee4e995bcb4c0e; version=bfbab62ca69f72bcd14ea30de1fb98f6080ad464 <7fe415e1cd8fa875be263670c0ab47109818abb6

Published CVSS scores

4.1Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/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.

Activity data is delayed. The latest report is Sep 28, 2026.

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No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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