---
id: CVE-2026-98586
title: >-
  kernel: sctp: hold asoc or transport before mod_timer() in timer handlers
  (CVE-2026-98586)
summary: >-
  A flaw was found in the Linux kernel's Stream Control Transmission Protocol
  (SCTP) subsystem. This vulnerability can lead to a Denial of Service (DoS)
  through a kernel crash. A race condition occurs between timer rearming and
  cleanup opera…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe: CWE-911
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 6
  - enterprise_linux 7
  - enterprise_linux 8
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-10-18'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T04:11:03+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98586.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98586.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98586'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2555030'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98586'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98586'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98586.mbox
  - url: 'https://git.kernel.org/stable/c/f7dea7eaea20fe9b80f8f77ba44d02b4a17f8050'
  - url: 'https://git.kernel.org/stable/c/f9d929026d487a988bfa12c065f892e823e5b6ab'
  - url: 'https://git.kernel.org/stable/c/9d3d39da054476e7aa05cd877b93ca73a9a77434'
  - url: 'https://git.kernel.org/stable/c/27c51a9b55b227309161c903f9ecfbf022516bc2'
  - url: 'https://git.kernel.org/stable/c/d18cb8fd1b6ba95c85de644203cfe1b071ff0c0f'
  - url: 'https://git.kernel.org/stable/c/35bf3b23c9a871f44c1453d85f8332be4e088dda'
  - url: 'https://git.kernel.org/stable/c/cae23ae3f7887a1cf8a75da38edcebeef695040f'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00173
epssPercentile: 0.06622
ingestedAt: '2026-10-18T15:45:12.252Z'
---

## Overview

A flaw was found in the Linux kernel's Stream Control Transmission Protocol (SCTP) subsystem. This vulnerability can lead to a Denial of Service (DoS) through a kernel crash. A race condition occurs between timer rearming and cleanup operations because the system modifies a timer before properly acquiring a reference to the associated transport object. An attacker able to generate SCTP traffic can trigger this timing window, causing a reference count underflow on an already freed memory object and resulting in system instability.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, 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 7, Red Hat Enterprise Linux 8, … · updated 2026-10-20 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98586.json)

**kernel: sctp: hold asoc or transport before mod_timer() in timer handlers** — rated Moderate by Red Hat. Released 2026-10-18, updated 2026-10-20.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- 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 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

## Remediation

Out of support scope