CVE-2025-22025Network attack vector

Service interruption via leaked delegation-recall references

Published Apr 16, 2025 · Updated Aug 5, 2026

Resource exhaustion in Linux kernel nfsd allows remote attackers to interrupt service by triggering failed NFSv4 delegation-recall queuing. In the nfsd4_run_cb failure path, nfsd retains the incremented dl_stid reference instead of calling nfs4_put_stid after callback work cannot be queued. A network peer that can reach an NFSv4 export can repeat conflicting opens to leak kernel objects, exhaust memory, and crash or hang the server.

CVSS severity7.5
High
EPSS probability0.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Linux kernel nfsd allows remote attackers to interrupt service by triggering failed NFSv4 delegation-recall queuing. In the nfsd4_run_cb failure path, nfsd retains the incremented dl_stid reference instead of calling nfs4_put_stid after callback work cannot be queued. A network peer that can reach an NFSv4 export can repeat conflicting opens to leak kernel objects, exhaust memory, and crash or hang the server.

The record

CVE
CVE-2025-22025
Published
Apr 16, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=2.6.35
  2. Affected versionversion=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <133f5e2a37ce08c82d24e8fba65e0a81deae4609
  3. Affected versionversion=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <230ca758453c63bd38e4d9f4a21db698f7abada8
  4. Affected versionversion=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <63b91c8ff4589f5263873b24c052447a28e10ef7
  5. Affected versionversion=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <9a81cde8c7ce65dd90fb47ceea93a45fc1a2fbd1
  6. Affected versionversion=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <b874cdef4e67e5150e07eff0eae1cbb21fb92da1
  7. Affected versionversion=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <cad3479b63661a399c9df1d0b759e1806e2df3c8
  8. Affected versionversion=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <cdb796137c57e68ca34518d53be53b679351eb86
  9. Affected versionversion=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <d96587cc93ec369031bcd7658c6adc719873c9fd

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.35; version=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <133f5e2a37ce08c82d24e8fba65e0a81deae4609; version=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <230ca758453c63bd38e4d9f4a21db698f7abada8; version=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <63b91c8ff4589f5263873b24c052447a28e10ef7; version=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <9a81cde8c7ce65dd90fb47ceea93a45fc1a2fbd1; version=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <b874cdef4e67e5150e07eff0eae1cbb21fb92da1; version=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <cad3479b63661a399c9df1d0b759e1806e2df3c8; version=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <cdb796137c57e68ca34518d53be53b679351eb86; version=b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf <d96587cc93ec369031bcd7658c6adc719873c9fd

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
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

See the directory against your own environment.

Your stack

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