---
id: CVE-2026-89595
title: >-
  kernel: fsnotify: Fix stale object mask after concurrent mark updates
  (CVE-2026-89595)
summary: >-
  A flaw was found in the Linux kernel's fsnotify subsystem, affecting fanotify
  and inotify. A race condition can occur during concurrent updates to event
  marks, where the object mask becomes stale. This can lead to a denial of
  service or in…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe: CWE-367
vendor: Red Hat
product: Red Hat OpenShift Container Platform 4
affected:
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T12:14:03+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89595.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89595.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89595'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532332'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89595'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89595'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89595.mbox
  - url: 'https://git.kernel.org/stable/c/947400af98b9e63841929d079a2c3ea0a8ba227b'
  - url: 'https://git.kernel.org/stable/c/ac8d8b599d466a129122bded77db3d0f8b96b461'
  - url: 'https://git.kernel.org/stable/c/e422777fdd4746de1109575c51e65038d4c5c1be'
  - url: 'https://git.kernel.org/stable/c/27d172b60eeca5c8fd51b246f9fb959067cf102b'
  - url: 'https://git.kernel.org/stable/c/2f09f08d602647fc4e328fc27ecb4c3008d10338'
  - url: 'https://git.kernel.org/stable/c/de75382d6e354b2b055df4896d12a91969f12090'
  - url: 'https://git.kernel.org/stable/c/343ae18e960f6c5f1d34d58a69750c62cd463228'
  - url: 'https://git.kernel.org/stable/c/92289e66639f62abc754c6f3bce5ead7e98e4ee2'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.0021
epssPercentile: 0.11558
ingestedAt: '2026-09-14T15:23:07.451Z'
---

## Overview

A flaw was found in the Linux kernel's fsnotify subsystem, affecting fanotify and inotify. A race condition can occur during concurrent updates to event marks, where the object mask becomes stale. This can lead to a denial of service or information disclosure, as events such as file modifications (e.g., FAN_MODIFY, IN_MODIFY) may not be properly reported to applications monitoring file system activity.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat OpenShift Container Platform 4 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89595.json)

**kernel: fsnotify: Fix stale object mask after concurrent mark updates** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-16.

Affected:

- Red Hat OpenShift Container Platform 4

No fix planned:

- Red Hat OpenShift Container Platform 4

## Remediation

Fix deferred