---
id: CVE-2026-89712
title: >-
  kernel: NFSD: restart ssc_expire_umount walk after dropping nfsd_ssc_lock
  (CVE-2026-89712)
summary: >-
  A flaw was found in the Linux kernel's Network File System Daemon (NFSD)
  component. A race condition exists where, during the processing of unmounted
  source-server mounts, a thread may temporarily release a lock. During this
  window, anothe…
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 9
affected:
  - enterprise_linux 10
  - enterprise_linux 6
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T17:07:07+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89712.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89712.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89712'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532255'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89712'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89712'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89712.mbox
  - url: 'https://git.kernel.org/stable/c/2b59029b8f24a99b5d844af2da3950d39d36eeea'
  - url: 'https://git.kernel.org/stable/c/d9e151fea5ed706c1284adacabd869b0be745db2'
  - url: 'https://git.kernel.org/stable/c/659ee3da073164e1e6e40dfcbc26eeed85845f93'
  - url: 'https://git.kernel.org/stable/c/60680ae7243b22de3d09be990d8e23bcfc4af837'
  - url: 'https://git.kernel.org/stable/c/77de363d9a1c8cd35f20482782c612cda085791a'
  - url: 'https://git.kernel.org/stable/c/4ed8d2317aef21cc2a9e5a55d6b59860b4b151a8'
  - url: 'https://git.kernel.org/stable/c/7377fa964b8aaf47cb04e5efcc4c82d15e8c2ce9'
  - url: 'https://git.kernel.org/stable/c/036c1b182f4da65363e79ec0ac276edc6b7296e5'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
  - score-dispute
epss: 0.00704
epssPercentile: 0.51875
scores:
  vendor: 7
  cna: 9.8
ingestedAt: '2026-09-14T15:23:07.449Z'
---

## Overview

A flaw was found in the Linux kernel's Network File System Daemon (NFSD) component. A race condition exists where, during the processing of unmounted source-server mounts, a thread may temporarily release a lock. During this window, another NFS Remote Procedure Call (RPC) thread can free memory that the first thread subsequently attempts to access. This use-after-free vulnerability could allow a remote attacker to cause a denial of service.

## 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-2026-89712.json)

**kernel: NFSD: restart ssc_expire_umount walk after dropping nfsd_ssc_lock** — 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