---
id: CVE-2026-98442
title: >-
  kernel: net/sched: act_ct: fix helper UAF due to extensions realloc
  (CVE-2026-98442)
summary: >-
  A flaw was found in the Linux kernel's traffic control connection tracking
  action (act_ct). An attacker capable of sending network traffic handled by the
  affected system can cause a Denial of Service (DoS) or kernel memory
  corruption throu…
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: vendor
cwe: CWE-825
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-10-18'
updated: '2026-10-24'
sourceUpdated: '2026-10-24T14:27:31+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98442.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98442.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98442'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2554848'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98442'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98442'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98442.mbox
  - url: 'https://git.kernel.org/stable/c/31f5fe29a572037ee19c233dfe506849940c484b'
  - url: 'https://git.kernel.org/stable/c/1679bbf5fbeac52a310b1a58b2b301bbf388bdbf'
  - url: 'https://git.kernel.org/stable/c/812c16a255e7773a544e88b39ae6daed25544d30'
  - url: 'https://git.kernel.org/stable/c/8988f4d11f3fba0ab38122178836c683ad516a05'
  - url: 'https://git.kernel.org/stable/c/dad19b59da050cb60d3f7023dac2a042a84bf0bd'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00129
epssPercentile: 0.02524
scores:
  vendor: 7.5
  cna: 7.8
ingestedAt: '2026-10-18T15:45:12.307Z'
---

## Overview

A flaw was found in the Linux kernel's traffic control connection tracking action (act_ct). An attacker capable of sending network traffic handled by the affected system can cause a Denial of Service (DoS) or kernel memory corruption through a use-after-free vulnerability. This issue occurs because connection tracking helpers record pointers to extension memory before all extensions are added, leaving invalid references when memory is subsequently reallocated.

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98442.json)

**kernel: net/sched: act_ct: fix helper UAF due to extensions realloc** — rated Important by Red Hat. Released 2026-10-18, updated 2026-10-24.

Affected:

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

No fix planned:

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

Not affected:

- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat OpenShift Container Platform 4

## Remediation

Affected

Workarounds / mitigations:

- --- CME Mitigation Guidance (2026-10-20) ---
Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.

The highest-value action is to ensure conntrack helper functions run only after all connection tracking extension…