---
id: CVE-2025-40187
title: 'net/sctp: fix a null dereference in sctp_disposition sctp_sf_do_5_1D_ce()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/sctp: fix a null dereference in sctp_disposition sctp_sf_do_5_1D_ce()

  If new_asoc->peer.adaptation_ind=0 and sctp_ulpevent_make_authkey=0
  and sctp_ulpevent_make_au…
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: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <
    1014b83778c8677f1d7a57c26dc728baa801ac62
  - >-
    Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <
    7f702f85df0266ed7b5bab81ba50394c92f3c928
  - >-
    Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <
    dbceedc0213e75bf3e9f9f9e2f66b10699d004fe
  - >-
    Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <
    025419f4e216a3ae0d0cec622262e98e8078c447
  - >-
    Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <
    c21f45cfa4a9526b34d76b397c9ef080668b6e73
  - >-
    Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <
    d0e8f1445c19b1786759ba72a38267e1449bab7e
  - >-
    Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <
    badbd79313e6591616c1b78e29a9b71efed7f035
  - >-
    Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <
    2f3119686ef50319490ccaec81a575973da98815
  - Linux 4.17
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-15T21:57:50.354384Z'
published: '2025-11-12'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:02:40.120Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-40187'
references:
  - url: 'https://git.kernel.org/stable/c/1014b83778c8677f1d7a57c26dc728baa801ac62'
  - url: 'https://git.kernel.org/stable/c/7f702f85df0266ed7b5bab81ba50394c92f3c928'
  - url: 'https://git.kernel.org/stable/c/dbceedc0213e75bf3e9f9f9e2f66b10699d004fe'
  - url: 'https://git.kernel.org/stable/c/025419f4e216a3ae0d0cec622262e98e8078c447'
  - url: 'https://git.kernel.org/stable/c/c21f45cfa4a9526b34d76b397c9ef080668b6e73'
  - url: 'https://git.kernel.org/stable/c/d0e8f1445c19b1786759ba72a38267e1449bab7e'
  - url: 'https://git.kernel.org/stable/c/badbd79313e6591616c1b78e29a9b71efed7f035'
  - url: 'https://git.kernel.org/stable/c/2f3119686ef50319490ccaec81a575973da98815'
tags:
  - cve.org
epss: 0.00638
epssPercentile: 0.49377
ingestedAt: '2026-10-15T22:48:25.550Z'
---

## Overview

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

net/sctp: fix a null dereference in sctp_disposition sctp_sf_do_5_1D_ce()

If new_asoc->peer.adaptation_ind=0 and sctp_ulpevent_make_authkey=0
and sctp_ulpevent_make_authkey() returns 0, then the variable
ai_ev remains zero and the zero will be dereferenced
in the sctp_ulpevent_free() function.

## Affected

- `Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b < 1014b83778c8677f1d7a57c26dc728baa801ac62`
- `Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b < 7f702f85df0266ed7b5bab81ba50394c92f3c928`
- `Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b < dbceedc0213e75bf3e9f9f9e2f66b10699d004fe`
- `Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b < 025419f4e216a3ae0d0cec622262e98e8078c447`
- `Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b < c21f45cfa4a9526b34d76b397c9ef080668b6e73`
- `Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b < d0e8f1445c19b1786759ba72a38267e1449bab7e`
- `Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b < badbd79313e6591616c1b78e29a9b71efed7f035`
- `Linux >= 30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b < 2f3119686ef50319490ccaec81a575973da98815`
- `Linux 4.17`

## Remediation

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