---
id: CVE-2026-89488
title: 'kernel: openvswitch: Fix CT limit teardown use-after-free (CVE-2026-89488)'
summary: >-
  A flaw was found in the Linux kernel's Open vSwitch (OVS) component. An
  unprivileged user, operating from a user and network namespace, can trigger a
  use-after-free vulnerability during network namespace teardown. This occurs
  because packe…
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 8
  - enterprise_linux 9
  - openshift_container_platform 4
  - enterprise_linux 6
published: '2026-09-11'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T10:47:46+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89488.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89488.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89488'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532407'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89488'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89488'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89488.mbox
  - url: 'https://git.kernel.org/stable/c/239f26589a6926db28c436e14f28517581ef1385'
  - url: 'https://git.kernel.org/stable/c/3b9369881b403f4cdbb11fa998554382bdcc3d8c'
  - url: 'https://git.kernel.org/stable/c/3b41d907400cc1dd1da9555b81dca422b1f44433'
  - url: 'https://git.kernel.org/stable/c/680f20d5937fa4d1367c59fe83091b78041015f5'
  - url: 'https://git.kernel.org/stable/c/bf4aaa7ea2579e24ed7de2e20578a875bebca011'
  - url: 'https://git.kernel.org/stable/c/e15407c3a8a005324f633cd46cd8fb58042c1157'
  - url: 'https://git.kernel.org/stable/c/6a6d36fadb8537d9b79e72c9fa51885ec0c33e10'
  - url: 'https://git.kernel.org/stable/c/403f96c32c9e24600093d7d0c61c17daeedca957'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00125
epssPercentile: 0.02574
scores:
  vendor: 7
  cna: 7.8
ingestedAt: '2026-09-14T15:23:07.452Z'
---

## Overview

A flaw was found in the Linux kernel's Open vSwitch (OVS) component. An unprivileged user, operating from a user and network namespace, can trigger a use-after-free vulnerability during network namespace teardown. This occurs because packet processing attempts to use connection tracking (CT) limit state after it has been freed, leading to a slab-use-after-free condition. This vulnerability could potentially lead to a denial of service.

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4, Red Hat Enterprise Linux 6 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89488.json)

**kernel: openvswitch: Fix CT limit teardown use-after-free** — rated Important by Red Hat. Released 2026-09-11, updated 2026-09-18.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat Enterprise Linux 6

No fix planned:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

Not affected:

- Red Hat Enterprise Linux 7

## Remediation

Affected