---
id: CVE-2026-74752
title: 'sctp: validate cookie AUTH state before use'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  sctp: validate cookie AUTH state before use

  When cookie authentication is disabled, COOKIE_ECHO restores fixed-size
  AUTH fields directly from peer-controlled cookie by…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-805
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 1f485649f52929d9937b346a920a522a7363e202 <
    4a4410de8dc6903d859c9e1731fc6dcee28bd072
  - >-
    Linux >= 1f485649f52929d9937b346a920a522a7363e202 <
    7f17984cfa697613800eb693e183b06884129bd3
  - >-
    Linux >= 1f485649f52929d9937b346a920a522a7363e202 <
    88619b117be1daf633ce32210570ce35a0bd1c98
  - >-
    Linux >= 1f485649f52929d9937b346a920a522a7363e202 <
    3dbb44d88b1e94dd31fe43588af7437b34b44d56
  - Linux 2.6.24
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-10-16T19:16:25.350604Z'
published: '2026-08-26'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:46:23.915Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-74752'
references:
  - url: 'https://git.kernel.org/stable/c/4a4410de8dc6903d859c9e1731fc6dcee28bd072'
  - url: 'https://git.kernel.org/stable/c/7f17984cfa697613800eb693e183b06884129bd3'
  - url: 'https://git.kernel.org/stable/c/88619b117be1daf633ce32210570ce35a0bd1c98'
  - url: 'https://git.kernel.org/stable/c/3dbb44d88b1e94dd31fe43588af7437b34b44d56'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74752.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-74752'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2524422'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-74752'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-74752'
  - url: >-
      https://lore.kernel.org/linux-cve-announce/2026082600-CVE-2026-74752-6509@gregkh/T
  - url: 'https://access.redhat.com/errata/RHSA-2026:85321'
  - url: 'https://access.redhat.com/errata/RHSA-2026:85773'
  - url: 'https://access.redhat.com/errata/RHSA-2026:85774'
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00524
epssPercentile: 0.44252
patched:
  - 10base_smtv
  - enterprise_linux_appstream_v_10
  - enterprise_linux_baseos_v_10
  - enterprise_linux_baseos_v_8
  - enterprise_linux_codeready_linux_builder_v_10
  - enterprise_linux_crb_v_8
  - enterprise_linux_hidden_v_10
  - enterprise_linux_real_time_for_nfv_v_10
  - enterprise_linux_nfv_v_8
  - enterprise_linux_real_time_v_10
  - enterprise_linux_rt_v_8
scores:
  cna: 9.8
  vendor: 8.8
ingestedAt: '2026-10-16T19:46:24.322Z'
---

## Overview

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

sctp: validate cookie AUTH state before use

When cookie authentication is disabled, COOKIE_ECHO restores fixed-size
AUTH fields directly from peer-controlled cookie bytes.  A forged RANDOM
length, HMAC list, or CHUNKS list can then reach association consumers
with lengths or identifiers that were never validated against the local
backing arrays.

A forged RANDOM length can cause out-of-bounds reads during key-vector
construction.  A forged HMAC identifier also caused a 32-byte write past
a zero-length AUTH chunk, providing a primitive for a local privilege
escalation chain.

Validate the cookie's RANDOM, HMACS, and CHUNKS parameters at the cookie
trust boundary before copying them into the association.  Reject invalid
types, malformed lengths, unsupported HMAC identifiers, HMAC lists
without SHA1, and forbidden chunk ids.

## Affected

- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 4a4410de8dc6903d859c9e1731fc6dcee28bd072`
- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 7f17984cfa697613800eb693e183b06884129bd3`
- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 88619b117be1daf633ce32210570ce35a0bd1c98`
- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 3dbb44d88b1e94dd31fe43588af7437b34b44d56`
- `Linux 2.6.24`

## Remediation

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

## Vendor advisories

- **RHSA-2026:85321** · Red Hat · fixed in: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Hidden (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), … · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:85321)
- **RHSA-2026:85773** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:85773)
- **RHSA-2026:85774** · Red Hat · fixed in: Red Hat Enterprise Linux NFV (v. 8), Red Hat Enterprise Linux RT (v. 8) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:85774)
- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 9 · updated 2026-10-20 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74752.json)