CVE-2023-53606Network attack vector

Service interruption via nfsd COPY reference leaks

Published Oct 4, 2025 · Updated Oct 4, 2025

Reference leaks in the nfsd COPY path in Linux allow remote attackers to interrupt service through NFSv4 COPY requests. When kthread_create fails during an asynchronous copy, nfsd4_copy retains its source and destination nfsd_file references instead of releasing them before return. Exposure requires an NFSv4 server to process COPY operations and a worker-thread creation failure; repeated leaks consume resources and can interrupt availability.

CVSS severity7.5
High
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reference leaks in the nfsd COPY path in Linux allow remote attackers to interrupt service through NFSv4 COPY requests. When kthread_create fails during an asynchronous copy, nfsd4_copy retains its source and destination nfsd_file references instead of releasing them before return. Exposure requires an NFSv4 server to process COPY operations and a worker-thread creation failure; repeated leaks consume resources and can interrupt availability.

The record

CVE
CVE-2023-53606
Published
Oct 4, 2025
Updated
Oct 4, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 4, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 4, 2025Record 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6ba434cb1a8d403ea9aad1b667c3ea3ad8b3191f
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <75b8c681c563ef7e85da6862354efc18d2a08b1b
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8f565846fbe8182961498d4cbe618b15076a683b
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b3169b6ffe036b549c296a9e71591d29a1fb3209
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fd63299db8090307eae66f2aef17c8f00aafa0a9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6ba434cb1a8d403ea9aad1b667c3ea3ad8b3191f; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <75b8c681c563ef7e85da6862354efc18d2a08b1b; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8f565846fbe8182961498d4cbe618b15076a683b; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b3169b6ffe036b549c296a9e71591d29a1fb3209; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fd63299db8090307eae66f2aef17c8f00aafa0a9

Published CVSS scores

7.5kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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