---
id: CVE-2026-89439
title: 'platform/x86: ISST: Add a NULL check for sst_inst[]'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  platform/x86: ISST: Add a NULL check for sst_inst[]

  To be consistent with other places, add a NULL check for failed socket
  loading by checking isst_common.sst_inst[].
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe:
  - CWE-476
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= d805456c712f93ba8a012430f2a93bec133b6ff4 <
    f7c9370dd1d3cedb80c635528271cab1d0bcb103
  - >-
    Linux >= d805456c712f93ba8a012430f2a93bec133b6ff4 <
    49a95fe1f64f41c2e8959e525aefdb10f23b293e
  - >-
    Linux >= d805456c712f93ba8a012430f2a93bec133b6ff4 <
    c280fcd53b938b70c7dee9ce1a66b32bd6e5ebaa
  - >-
    Linux >= d805456c712f93ba8a012430f2a93bec133b6ff4 <
    ef7975af15126dd70ace519da7bb33f2848b9064
  - >-
    Linux >= d805456c712f93ba8a012430f2a93bec133b6ff4 <
    3de2776e9d7073765c10c2326c2bda5926811ea6
  - Linux 6.4
published: '2026-09-11'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:47:27.422Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89439'
references:
  - url: 'https://git.kernel.org/stable/c/f7c9370dd1d3cedb80c635528271cab1d0bcb103'
  - url: 'https://git.kernel.org/stable/c/49a95fe1f64f41c2e8959e525aefdb10f23b293e'
  - url: 'https://git.kernel.org/stable/c/c280fcd53b938b70c7dee9ce1a66b32bd6e5ebaa'
  - url: 'https://git.kernel.org/stable/c/ef7975af15126dd70ace519da7bb33f2848b9064'
  - url: 'https://git.kernel.org/stable/c/3de2776e9d7073765c10c2326c2bda5926811ea6'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89439.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89439'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532216'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89439'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89439'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89439.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00206
epssPercentile: 0.10582
ingestedAt: '2026-09-14T00:35:28.531Z'
---

## Overview

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

platform/x86: ISST: Add a NULL check for sst_inst[]

To be consistent with other places, add a NULL check for failed socket
loading by checking isst_common.sst_inst[].

## Affected

- `Linux >= d805456c712f93ba8a012430f2a93bec133b6ff4 < f7c9370dd1d3cedb80c635528271cab1d0bcb103`
- `Linux >= d805456c712f93ba8a012430f2a93bec133b6ff4 < 49a95fe1f64f41c2e8959e525aefdb10f23b293e`
- `Linux >= d805456c712f93ba8a012430f2a93bec133b6ff4 < c280fcd53b938b70c7dee9ce1a66b32bd6e5ebaa`
- `Linux >= d805456c712f93ba8a012430f2a93bec133b6ff4 < ef7975af15126dd70ace519da7bb33f2848b9064`
- `Linux >= d805456c712f93ba8a012430f2a93bec133b6ff4 < 3de2776e9d7073765c10c2326c2bda5926811ea6`
- `Linux 6.4`

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89439.json)