---
id: CVE-2026-89696
title: >-
  kernel: nfsd: block non-SAVEFH ops after FOREIGN PUTFH to prevent NULL deref
  (CVE-2026-89696)
summary: >-
  A flaw was found in the Linux kernel's Network File System (NFS) daemon
  (nfsd). A remote client can exploit this by sending a specially crafted NFS
  COMPOUND request. This request, when processed, can lead to a NULL pointer
  dereference in t…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe: CWE-476
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: '2026-09-21'
sourceUpdated: '2026-09-21T11:52:00+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89696.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89696.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89696'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532408'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89696'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89696'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89696.mbox
  - url: 'https://git.kernel.org/stable/c/ffdc844e673d2bcb2af8c8c3eef8cdea59d0bf32'
  - url: 'https://git.kernel.org/stable/c/00c84f4eec715e501efc080a5670114189e42507'
  - url: 'https://git.kernel.org/stable/c/2d9846fd1c767920fddd4bde30eb35cd2969df13'
  - url: 'https://git.kernel.org/stable/c/977e6f006a7a3ffc4216ae6034f768f8de6fd138'
  - url: 'https://git.kernel.org/stable/c/35f248bd40b47b229d4999581df45b97daadd977'
  - url: 'https://git.kernel.org/stable/c/311f7d926630940650447cbd1c932b076b40a6c4'
  - url: 'https://git.kernel.org/stable/c/bf4d338dc8625d70c7f2cb0657d66851a7ac9154'
  - url: 'https://git.kernel.org/stable/c/c59738a00aa51b16adc1b5ceb7c80877168efb4d'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
  - score-dispute
epss: 0.00762
epssPercentile: 0.53903
scores:
  vendor: 5.5
  cna: 7.5
ingestedAt: '2026-09-14T15:23:07.449Z'
---

## Overview

A flaw was found in the Linux kernel's Network File System (NFS) daemon (nfsd). A remote client can exploit this by sending a specially crafted NFS COMPOUND request. This request, when processed, can lead to a NULL pointer dereference in the nfsd kthread, causing the system to crash and resulting in a Denial of Service (DoS).

## 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 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89696.json)

**kernel: nfsd: block non-SAVEFH ops after FOREIGN PUTFH to prevent NULL deref** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-21.

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