---
id: CVE-2026-98130
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  sctp: fix a TOCTOU race in SCTP_CMD_TIMER_START

  The SCTP_CMD_TIMER_START handler checks timer_pending() before calling
  timer_reduce()
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  sctp: fix a TOCTOU race in SCTP_CMD_TIMER_START

  The SCTP_CMD_TIMER_START handler checks timer_pending() before calling
  timer_reduce(). The timer can expire and detach …
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 20a785aa52c82246055a089e55df9dac47d67da1 <
    e42ba56281ca3ae2dcb3558bebee9a1c9a4831d9
  - >-
    Linux >= 20a785aa52c82246055a089e55df9dac47d67da1 <
    00b841bac10230c557be6b38efc48508198fe23e
  - >-
    Linux >= 20a785aa52c82246055a089e55df9dac47d67da1 <
    3d698d1e6c8bc41e3e1707777a016f1bdd07842d
  - >-
    Linux >= 20a785aa52c82246055a089e55df9dac47d67da1 <
    2188569e7e1b0bc3f3b557dc97ab7a02befc11c8
  - Linux 9c0a4652f750afe3b4468cbcd9335b244ce2facd
  - Linux 70989e501fbce502198d82da88358ce453575a05
  - Linux 085bb270b4b1168c93afb37bbafc881207d15443
  - Linux >= 4.19.126 < 4.20
  - Linux >= 5.4.44 < 5.5
  - Linux >= 5.6.16 < 5.7
  - Linux 5.7
published: '2026-09-25'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T15:18:06.713'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98130'
references:
  - url: 'https://git.kernel.org/stable/c/00b841bac10230c557be6b38efc48508198fe23e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2188569e7e1b0bc3f3b557dc97ab7a02befc11c8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3d698d1e6c8bc41e3e1707777a016f1bdd07842d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e42ba56281ca3ae2dcb3558bebee9a1c9a4831d9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-25T11:06:38.814Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

sctp: fix a TOCTOU race in SCTP_CMD_TIMER_START

The SCTP_CMD_TIMER_START handler checks timer_pending() before calling
timer_reduce(). The timer can expire and detach between these operations,
causing timer_reduce() to rearm the timer without taking the association
reference required for the newly armed timer.

The timer callback later unconditionally drops its association reference,
which can leave the association reference count unbalanced and result in
use-after-free during association teardown.

Use the return value of timer_reduce() to determine whether the timer was
actually armed. Take the association reference only when timer_reduce()
successfully starts a new timer, closing the race between checking the
timer state and rearming it.

This issue was reported by Nico Yip (@_cyeaa_) working with TrendAI Zero
Day Initiative.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.