CVE-2026-89694Network attack vector

Cross-client copy cancellation via unchecked stateid ownership

Published Sep 11, 2026 · Updated Sep 11, 2026

Improper authorization in Linux 5.6 allows remote authenticated users to cancel another client's NFSv4.2 copy-notify state. The nfsd manage_cpntf_state() OFFLOAD_CANCEL path frees the state selected by a cyclic, guessable ID without comparing its recorded creator client ID to the requester. An authenticated NFSv4.2 client can invalidate another client's pending copy-notify state, interrupting that client's server-side copy workflow.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper authorization in Linux 5.6 allows remote authenticated users to cancel another client's NFSv4.2 copy-notify state. The nfsd manage_cpntf_state() OFFLOAD_CANCEL path frees the state selected by a cyclic, guessable ID without comparing its recorded creator client ID to the requester. An authenticated NFSv4.2 client can invalidate another client's pending copy-notify state, interrupting that client's server-side copy workflow.

The record

CVE
CVE-2026-89694
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.6
  2. Affected versionversion=ce0887ac96d35c7105090e166bb0807dc0a0e838 <6bdbfab96e0cf25e5f57dac5c09dc1749751a4bf
  3. Affected versionversion=ce0887ac96d35c7105090e166bb0807dc0a0e838 <b1eca07303594ca27f5dc360a6946bd7e1f5b04c
  4. Affected versionversion=ce0887ac96d35c7105090e166bb0807dc0a0e838 <b42dc26a14b4ad5d6daaada11ec4c70744141c25
  5. Affected versionversion=ce0887ac96d35c7105090e166bb0807dc0a0e838 <d801906165cb5cc250d5cbe44935594e170be3e2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.6; version=ce0887ac96d35c7105090e166bb0807dc0a0e838 <6bdbfab96e0cf25e5f57dac5c09dc1749751a4bf; version=ce0887ac96d35c7105090e166bb0807dc0a0e838 <b1eca07303594ca27f5dc360a6946bd7e1f5b04c; version=ce0887ac96d35c7105090e166bb0807dc0a0e838 <b42dc26a14b4ad5d6daaada11ec4c70744141c25; version=ce0887ac96d35c7105090e166bb0807dc0a0e838 <d801906165cb5cc250d5cbe44935594e170be3e2

Published CVSS scores

No CVSS assessment is available in this record.

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo