CVE-2023-53791Public exploit

Kernel warning via mismatched block-device holder

Published Dec 9, 2025 · Updated May 11, 2026

A holder mismatch in Linux 6.5 allows local users to trigger a kernel warning by racing MD device addition and removal through sysfs. export_rdev() can acquire a block device with rdev after mddev->external changes to 1 but release it with claim_rdev, pairing blkdev_get_by_dev() and blkdev_put() with different holders. Reachability requires local write access to MD sysfs controls and the external-metadata transition; the published reproducer demonstrates a warning, not a crash or code execution.

CVSS severity7.0
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

A holder mismatch in Linux 6.5 allows local users to trigger a kernel warning by racing MD device addition and removal through sysfs. export_rdev() can acquire a block device with rdev after mddev->external changes to 1 but release it with claim_rdev, pairing blkdev_get_by_dev() and blkdev_put() with different holders. Reachability requires local write access to MD sysfs controls and the external-metadata transition; the published reproducer demonstrates a warning, not a crash or code execution.

The record

CVE
CVE-2023-53791
Published
Dec 9, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Dec 9, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=6.5
  2. Affected versionversion=a1d7671910965ca9f8f0377e7e3bfd1179fba4d8 <99892147f028d711f9d40fefad4f33632593864c
  3. Affected versionversion=a1d7671910965ca9f8f0377e7e3bfd1179fba4d8 <99fcd427178d0f58f5520f8f01df727f8eaeb2c7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=6.5; version=a1d7671910965ca9f8f0377e7e3bfd1179fba4d8 <99892147f028d711f9d40fefad4f33632593864c; version=a1d7671910965ca9f8f0377e7e3bfd1179fba4d8 <99fcd427178d0f58f5520f8f01df727f8eaeb2c7

Published CVSS scores

7.0Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/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.

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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
Privilegesadmin
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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