---
id: CVE-2026-89632
title: >-
  kernel: smb: client: fix use-before-check of ReparseDataLength in
  reparse_buf_ptr() (CVE-2026-89632)
summary: >-
  A flaw was found in the Linux kernel's Server Message Block (SMB) client. A
  malicious server could exploit this vulnerability by sending specially crafted
  data, leading to an out-of-bounds read. This occurs because the
  `reparse_buf_ptr()` …
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: vendor
cwe: CWE-125
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 8
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T20:12:42+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89632.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89632.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89632'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532415'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89632'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89632'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89632.mbox
  - url: 'https://git.kernel.org/stable/c/05f78e6cf34ea3a285053bd5999e08e8ac298bd5'
  - url: 'https://git.kernel.org/stable/c/711cf71300d7992f450600df8864917d3538679f'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00318
epssPercentile: 0.25015
scores:
  vendor: 6.3
  cna: 8.2
ingestedAt: '2026-09-14T15:23:07.473Z'
---

## Overview

A flaw was found in the Linux kernel's Server Message Block (SMB) client. A malicious server could exploit this vulnerability by sending specially crafted data, leading to an out-of-bounds read. This occurs because the `reparse_buf_ptr()` function reads data before properly validating the buffer size, allowing it to access memory beyond the intended boundary.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89632.json)

**kernel: smb: client: fix use-before-check of ReparseDataLength in reparse_buf_ptr()** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-18.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

No fix planned:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

Not affected:

- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7

## Remediation

Affected