---
id: CVE-2026-89687
title: 'nfsd: ensure nfsd_file_do_acquire() does not use a non-opened file'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfsd: ensure nfsd_file_do_acquire() does not use a non-opened file

  ->atomic_open is permitted to return success without actually opening
  the file.  It indicates this b…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-908
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 64a989dbd144e0622371396461b11335459692d2 <
    a95a1cffacd0203100297001719160160f443dd6
  - >-
    Linux >= 64a989dbd144e0622371396461b11335459692d2 <
    5859cc01fee06a2cd7458905a9593082fbab06e1
  - Linux 7.0
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:51:00.577Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89687'
references:
  - url: 'https://git.kernel.org/stable/c/a95a1cffacd0203100297001719160160f443dd6'
  - url: 'https://git.kernel.org/stable/c/5859cc01fee06a2cd7458905a9593082fbab06e1'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89687.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89687'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532086'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89687'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89687'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89687.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00488
epssPercentile: 0.41785
scores:
  cna: 7.5
  vendor: 5.5
ingestedAt: '2026-09-14T15:23:07.472Z'
---

## Overview

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

nfsd: ensure nfsd_file_do_acquire() does not use a non-opened file

->atomic_open is permitted to return success without actually opening
the file.  It indicates this by calling finish_no_open().
This means dentry_create() can return a file which hasn't been opened.
This is extremely unlikely as ->atomic_open handlers typically
use finish_no_open() only for already existing files, and dentry_create()
isn't called in that case, and the parent being locked should prevent
races.

However out of an abundance of caution it seems wise to teach nfsd to
only use the file returned by dentry_create() if FMODE_OPENED is set,
indicating that it has in fact been opened.

## Affected

- `Linux >= 64a989dbd144e0622371396461b11335459692d2 < a95a1cffacd0203100297001719160160f443dd6`
- `Linux >= 64a989dbd144e0622371396461b11335459692d2 < 5859cc01fee06a2cd7458905a9593082fbab06e1`
- `Linux 7.0`

## 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 OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat OpenShift Container Platform 4 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89687.json)