CVE-2025-38709Public exploit

Service interruption via unlocked loop-device resizing

Published Sep 4, 2025 · Updated May 11, 2026

Improper locking in affected Linux kernel revisions allows local users to interrupt service by resizing a mounted loop device. The loop_set_block_size function changes the device's logical block size without first obtaining exclusive ownership, leaving it inconsistent with the mounted filesystem's superblock. Access to issue LOOP_SET_BLOCK_SIZE against a loop device held by a mounted filesystem is required; the demonstrated result is a kernel warning and inconsistent buffer accounting.

CVSS severity5.5
Medium
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper locking in affected Linux kernel revisions allows local users to interrupt service by resizing a mounted loop device. The loop_set_block_size function changes the device's logical block size without first obtaining exclusive ownership, leaving it inconsistent with the mounted filesystem's superblock. Access to issue LOOP_SET_BLOCK_SIZE against a loop device held by a mounted filesystem is required; the demonstrated result is a kernel warning and inconsistent buffer accounting.

The record

CVE
CVE-2025-38709
Published
Sep 4, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 4, 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=4.14
  2. Affected versionversion=89e4fdecb51cf5535867026274bc97de9480ade5 <139a000d20f2f38ce34296feddd641d730fe1c08
  3. Affected versionversion=89e4fdecb51cf5535867026274bc97de9480ade5 <457d2c5e112fd08dc1039b1ae39a83ec1782360d
  4. Affected versionversion=89e4fdecb51cf5535867026274bc97de9480ade5 <5d67b30aefeb7a949040bbb1b4e3b84c5d29a624
  5. Affected versionversion=89e4fdecb51cf5535867026274bc97de9480ade5 <7e49538288e523427beedd26993d446afef1a6fb
  6. Affected versionversion=89e4fdecb51cf5535867026274bc97de9480ade5 <b928438cc87c0bf7ae078e4b7b6e14261e84c5c5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.14; version=89e4fdecb51cf5535867026274bc97de9480ade5 <139a000d20f2f38ce34296feddd641d730fe1c08; version=89e4fdecb51cf5535867026274bc97de9480ade5 <457d2c5e112fd08dc1039b1ae39a83ec1782360d; version=89e4fdecb51cf5535867026274bc97de9480ade5 <5d67b30aefeb7a949040bbb1b4e3b84c5d29a624; version=89e4fdecb51cf5535867026274bc97de9480ade5 <7e49538288e523427beedd26993d446afef1a6fb; version=89e4fdecb51cf5535867026274bc97de9480ade5 <b928438cc87c0bf7ae078e4b7b6e14261e84c5c5

Published CVSS scores

6.4Oracle LinuxCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
6.4Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
5.5NIST NVDCVSS: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

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

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Technologies

Your stack

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Your stack

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