---
id: CVE-2026-89694
title: >-
  kernel: nfsd: check client ownership when cancelling a copy-notify stateid
  (CVE-2026-89694)
summary: >-
  A flaw was found in the Linux kernel's NFSv4.2 server (nfsd). An authenticated
  NFSv4.2 client could exploit a vulnerability in the `manage_cpntf_state()`
  function by guessing a state identifier. This improper ownership check allows
  the cli…
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: vendor
cwe: CWE-639
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 6
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T12:14:12+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89694.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89694.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89694'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532327'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89694'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89694'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89694.mbox
  - url: 'https://git.kernel.org/stable/c/6bdbfab96e0cf25e5f57dac5c09dc1749751a4bf'
  - url: 'https://git.kernel.org/stable/c/b1eca07303594ca27f5dc360a6946bd7e1f5b04c'
  - url: 'https://git.kernel.org/stable/c/b42dc26a14b4ad5d6daaada11ec4c70744141c25'
  - url: 'https://git.kernel.org/stable/c/d801906165cb5cc250d5cbe44935594e170be3e2'
  - url: 'https://git.kernel.org/stable/c/88daaed26e17e1c7e851859b5bbb4f0e1ab6d0e9'
  - url: 'https://git.kernel.org/stable/c/81b2cfe767943922eca906a2a5af23a0ce5d0f35'
  - url: 'https://git.kernel.org/stable/c/6bba72b8ee68ad631b94bd439592cba46de54d7d'
  - url: 'https://git.kernel.org/stable/c/75268f6cfe26b09a7e4d3216367e87fe9e2a26aa'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.0021
epssPercentile: 0.11547
ingestedAt: '2026-09-14T15:23:07.449Z'
---

## Overview

A flaw was found in the Linux kernel's NFSv4.2 server (nfsd). An authenticated NFSv4.2 client could exploit a vulnerability in the `manage_cpntf_state()` function by guessing a state identifier. This improper ownership check allows the client to cancel and free another client's copy-notify stateid, leading to a Denial of Service (DoS) for the legitimate client.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89694.json)

**kernel: nfsd: check client ownership when cancelling a copy-notify stateid** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-16.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

No fix planned:

- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

Not affected:

- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8

## Remediation

Out of support scope