---
id: CVE-2026-89683
title: 'nfsd: fix dentry ref leak on V4ROOT export filehandle lookup'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfsd: fix dentry ref leak on V4ROOT export filehandle lookup

  nfsd_set_fh_dentry() leaks the dentry reference from
  exportfs_decode_fh_raw() when the NFS3_FHSIZE or NFS_…
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: Linux
product: Linux
affected:
  - >-
    Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 <
    d493cf57f4c4dae5396cd6ad41e5c209d0615a81
  - >-
    Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 <
    c1ae0f973bcba5730871e35976a0ab6878fdac34
  - >-
    Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 <
    11db8df188b34bdb8c6a3a0bf438e5fc8cd75aca
  - >-
    Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 <
    6247023fbbec1325029f2d5f2a7cdc0f9f9ea15a
  - Linux 6.12
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:50:56.607Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89683'
references:
  - url: 'https://git.kernel.org/stable/c/d493cf57f4c4dae5396cd6ad41e5c209d0615a81'
  - url: 'https://git.kernel.org/stable/c/c1ae0f973bcba5730871e35976a0ab6878fdac34'
  - url: 'https://git.kernel.org/stable/c/11db8df188b34bdb8c6a3a0bf438e5fc8cd75aca'
  - url: 'https://git.kernel.org/stable/c/6247023fbbec1325029f2d5f2a7cdc0f9f9ea15a'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89683.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89683'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532313'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89683'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89683'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89683.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00175
epssPercentile: 0.06998
ingestedAt: '2026-09-14T11:11:19.885Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

nfsd: fix dentry ref leak on V4ROOT export filehandle lookup

nfsd_set_fh_dentry() leaks the dentry reference from
exportfs_decode_fh_raw() when the NFS3_FHSIZE or NFS_FHSIZE
switch cases detect NFSEXP_V4ROOT and goto out. The out: label
calls exp_put() but never dput(dentry), and fhp->fh_dentry was
never assigned so fh_put() cannot compensate.

A crafted NFSv3 filehandle targeting a V4ROOT export's fsid
triggers the leak on every request.

## Affected

- `Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < d493cf57f4c4dae5396cd6ad41e5c209d0615a81`
- `Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < c1ae0f973bcba5730871e35976a0ab6878fdac34`
- `Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < 11db8df188b34bdb8c6a3a0bf438e5fc8cd75aca`
- `Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < 6247023fbbec1325029f2d5f2a7cdc0f9f9ea15a`
- `Linux 6.12`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89683.json)