---
id: CVE-2026-89706
title: >-
  kernel: nfsd: Reset write verifier when async COPY writeback fails
  (CVE-2026-89706)
summary: >-
  A flaw was found in the Linux kernel's nfsd component. When an asynchronous
  (async) copy writeback operation fails, the server's write verifier is not
  properly reset. This can lead to a client incorrectly assuming that data has
  been made d…
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-367
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: '2026-09-16T05:50:14+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89706.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89706.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89706'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532347'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89706'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89706'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89706.mbox
  - url: 'https://git.kernel.org/stable/c/cc5f7cef0659a27c13dd33edd8e2f79257b095c6'
  - url: 'https://git.kernel.org/stable/c/c6d2f6372c7e0f76b9c148ff7696aec64da0b5b7'
  - url: 'https://git.kernel.org/stable/c/8a08ffe73eb2aa6bc6f88763da7e2b55bab6493a'
  - url: 'https://git.kernel.org/stable/c/6b13d26cc21b6320a3c61d5e4cee2ce9a589b181'
  - url: 'https://git.kernel.org/stable/c/31d4d0a62ec4bafbcdbad142f11ab1f90794b1d0'
  - url: 'https://git.kernel.org/stable/c/591134e059e3456180244a826d6917cdc183140b'
  - url: 'https://git.kernel.org/stable/c/bf0cd31a9abcb728c17d79b4c2cc533612a8b6af'
  - url: 'https://git.kernel.org/stable/c/f5cb2276954cb80987a93ef9f9dfbfdbfc0f10b9'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00511
epssPercentile: 0.42643
scores:
  vendor: 7
  cna: 7.5
ingestedAt: '2026-09-14T15:23:07.449Z'
---

## Overview

A flaw was found in the Linux kernel's nfsd component. When an asynchronous (async) copy writeback operation fails, the server's write verifier is not properly reset. This can lead to a client incorrectly assuming that data has been made durable, resulting in the silent loss of data that was intended to be copied.

## 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-2026-89706.json)

**kernel: nfsd: Reset write verifier when async COPY writeback fails** — 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
- Red Hat OpenShift Container Platform 4

## Remediation

Out of support scope