---
id: CVE-2026-89670
title: 'kernel: nfsd: hold rcu across localio cmpxchg retry (CVE-2026-89670)'
summary: >-
  A flaw was found in the Linux kernel's Network File System Daemon (nfsd)
  component. A race condition exists in the `nfsd_open_local_fh()` function
  where an `nfsd_file` object can be freed and its memory recycled while another
  process attem…
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-825
vendor: Red Hat
product: Red Hat Enterprise Linux 10
affected:
  - enterprise_linux 10
published: '2026-09-11'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T22:37:22+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89670.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89670.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89670'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532286'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89670'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89670'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89670.mbox
  - url: 'https://git.kernel.org/stable/c/559570f91a7d4d199a72105e4980bef791f4cbf1'
  - url: 'https://git.kernel.org/stable/c/58884694978a3d7d111edb433d7fd6a6c5af2f34'
  - url: 'https://git.kernel.org/stable/c/763c0bad872368304db718f79af7e93048885c67'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00161
epssPercentile: 0.05761
scores:
  vendor: 7.5
  cna: 7.8
ingestedAt: '2026-09-14T15:23:07.473Z'
---

## Overview

A flaw was found in the Linux kernel's Network File System Daemon (nfsd) component. A race condition exists in the `nfsd_open_local_fh()` function where an `nfsd_file` object can be freed and its memory recycled while another process attempts to access it. This can lead to a use-after-free vulnerability, allowing an attacker to potentially cause memory corruption, disclose sensitive information, or execute arbitrary code.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89670.json)

**kernel: nfsd: hold rcu across localio cmpxchg retry** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-18.

Affected:

- Red Hat Enterprise Linux 10

No fix planned:

- Red Hat Enterprise Linux 10

Not affected:

- 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

## Remediation

Affected