---
id: CVE-2026-68376
title: 'sctp: fix auth_hmacs array size in struct sctp_cookie'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  sctp: fix auth_hmacs array size in struct sctp_cookie

  The auth_hmacs array in struct sctp_cookie is supposed to store a complete
  SCTP_AUTH_HMAC_ALGO parameter, which c…
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'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 1f485649f52929d9937b346a920a522a7363e202 <
    317731d01b03c529809df36d3a7d149677a8729d
  - >-
    Linux >= 1f485649f52929d9937b346a920a522a7363e202 <
    0528485f27016a42804abe01aa61b39d85fa803e
  - >-
    Linux >= 1f485649f52929d9937b346a920a522a7363e202 <
    ee5e65964f456adfe14d526fba0bd055de98ecf3
  - >-
    Linux >= 1f485649f52929d9937b346a920a522a7363e202 <
    0b4414e43e0861d67276031cc21401d7e87de3da
  - >-
    Linux >= 1f485649f52929d9937b346a920a522a7363e202 <
    d0a59ba58578e2b330fff80a44fe519f3ba7d8c7
  - >-
    Linux >= 1f485649f52929d9937b346a920a522a7363e202 <
    a8d20ba0ab518c9ccbcde258f25fc1ee6e51d5db
  - >-
    Linux >= 1f485649f52929d9937b346a920a522a7363e202 <
    3aa40c3bccac2312ea7cf97f329190637f972b5d
  - >-
    Linux >= 1f485649f52929d9937b346a920a522a7363e202 <
    e0b5252a59383b77d1b8dbeda00b7184dd95f4d3
  - Linux 2.6.24
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:47:35.941607Z'
exploitAvailable: true
published: '2026-08-10'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:53:09.967Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-68376'
references:
  - url: 'https://git.kernel.org/stable/c/317731d01b03c529809df36d3a7d149677a8729d'
  - url: 'https://git.kernel.org/stable/c/0528485f27016a42804abe01aa61b39d85fa803e'
  - url: 'https://git.kernel.org/stable/c/ee5e65964f456adfe14d526fba0bd055de98ecf3'
  - url: 'https://git.kernel.org/stable/c/0b4414e43e0861d67276031cc21401d7e87de3da'
  - url: 'https://git.kernel.org/stable/c/d0a59ba58578e2b330fff80a44fe519f3ba7d8c7'
  - url: 'https://git.kernel.org/stable/c/a8d20ba0ab518c9ccbcde258f25fc1ee6e51d5db'
  - url: 'https://git.kernel.org/stable/c/3aa40c3bccac2312ea7cf97f329190637f972b5d'
  - url: 'https://git.kernel.org/stable/c/e0b5252a59383b77d1b8dbeda00b7184dd95f4d3'
tags:
  - cve.org
  - exploit-available
epss: 0.00495
epssPercentile: 0.41106
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/gagaltotal/CVE-2026-68376-Ubuntu-7.0.0-30-Poc'
  checkedAt: '2026-10-16T17:25:21.017Z'
ingestedAt: '2026-10-16T17:24:46.862Z'
---

## Overview

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

sctp: fix auth_hmacs array size in struct sctp_cookie

The auth_hmacs array in struct sctp_cookie is supposed to store a complete
SCTP_AUTH_HMAC_ALGO parameter, which consists of a struct sctp_paramhdr
followed by N HMAC identifiers.

However, the array size was calculated using an extra 2 bytes instead of
sizeof(struct sctp_paramhdr), which is 4 bytes. When four HMAC identifiers
are configured, the HMAC-ALGO parameter stored in the endpoint is larger
than the auth_hmacs buffer in the cookie.

As a result, sctp_association_init() copies beyond the end of auth_hmacs
when initializing the association, corrupting the adjacent auth_chunks
field. This can lead to an invalid HMAC identifier being accepted and later
cause an out-of-bounds read in sctp_auth_get_hmac().

Fix the array size calculation by including the full SCTP parameter header
size.

## Affected

- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 317731d01b03c529809df36d3a7d149677a8729d`
- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 0528485f27016a42804abe01aa61b39d85fa803e`
- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < ee5e65964f456adfe14d526fba0bd055de98ecf3`
- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 0b4414e43e0861d67276031cc21401d7e87de3da`
- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < d0a59ba58578e2b330fff80a44fe519f3ba7d8c7`
- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < a8d20ba0ab518c9ccbcde258f25fc1ee6e51d5db`
- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 3aa40c3bccac2312ea7cf97f329190637f972b5d`
- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < e0b5252a59383b77d1b8dbeda00b7184dd95f4d3`
- `Linux 2.6.24`

## Remediation

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