---
id: CVE-2026-89707
title: 'kernel: nfsd: release path refs on follow_down() error (CVE-2026-89707)'
summary: >-
  A flaw was found in the Linux kernel's nfsd component. An authenticated
  Network File System (NFS) client can exploit this vulnerability by triggering
  a failed cross-mount operation through `nfsd_lookup_dentry` or the NFSv4
  READDIR encode p…
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-911
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 6
  - enterprise_linux 7
  - enterprise_linux 8
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-15'
sourceUpdated: '2026-09-15T12:46:55+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89707.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89707.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89707'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532441'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89707'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89707'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89707.mbox
  - url: 'https://git.kernel.org/stable/c/085cfde7c2186acaad103f02d2c25435ad5224e9'
  - url: 'https://git.kernel.org/stable/c/194316df81263519156ebe714c4a286bee00e5be'
  - url: 'https://git.kernel.org/stable/c/467d56fd3ff57447a790c6dc3ede2d02a947d224'
  - url: 'https://git.kernel.org/stable/c/2bc4343308d85ee4e0dd3877b384306c96f114c2'
  - url: 'https://git.kernel.org/stable/c/6cba08dc1922140d260cfeb30bbda4ee1bf869d8'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00603
epssPercentile: 0.47572
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. An authenticated Network File System (NFS) client can exploit this vulnerability by triggering a failed cross-mount operation through `nfsd_lookup_dentry` or the NFSv4 READDIR encode path. This leads to a reference count leak, which inflates `mnt_count` and `d_count`, blocking unmounting operations and pinning directory entries against the shrinker. This can result in a Denial of Service (DoS) condition.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, 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 7, Red Hat Enterprise Linux 8, … · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89707.json)

**kernel: nfsd: release path refs on follow_down() error** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-15.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- 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 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

## Remediation

Out of support scope