---
id: CVE-2026-98603
title: 'kernel: kernel: Denial of service via race condition in ovpn (CVE-2026-98603)'
summary: >-
  A flaw was found in the Linux kernel's OpenVPN (ovpn) module. A local user can
  cause a Denial of Service (DoS) or network disruption during concurrent
  network traffic when an outdated local source address is cleared. Because the
  address is…
severity: low
cvss: 2.5
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L'
cvssSource: vendor
cwe: CWE-20
vendor: Red Hat
product: Red Hat Enterprise Linux 10
affected:
  - enterprise_linux 10
published: '2026-10-18'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T08:12:45+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98603.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98603.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98603'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2554975'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98603'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98603'
  - url: 'https://git.kernel.org/stable/c/72bd1bea37ea2c8553938f086bf48ccd2147dfe1'
  - url: 'https://git.kernel.org/stable/c/7d8104988f423572df1f3347ce578037b1043f34'
  - url: 'https://git.kernel.org/stable/c/c44a04722f7dae9a45a101b8e100931ab59f1c18'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00198
epssPercentile: 0.09494
ingestedAt: '2026-10-18T15:45:12.247Z'
---

## Overview

A flaw was found in the Linux kernel's OpenVPN (ovpn) module. A local user can cause a Denial of Service (DoS) or network disruption during concurrent network traffic when an outdated local source address is cleared. Because the address is modified in place without proper synchronization, concurrent transmission operations may read a torn, partially updated address, leading to incorrect routing and packet transmission failures.

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-10-20 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98603.json)

**kernel: kernel: Denial of service via race condition in ovpn** — rated Low by Red Hat. Released 2026-10-18, updated 2026-10-20.

Affected:

- Red Hat Enterprise Linux 10

No fix planned:

- Red Hat Enterprise Linux 10

## Remediation

Fix deferred

Workarounds / mitigations:

- Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.