---
id: CVE-2026-89634
title: >-
  kernel: smb: client: fix ALIGN() overflow in symlink_data() error context loop
  (CVE-2026-89634)
summary: >-
  A flaw was found in the Server Message Block (SMB) client within the Linux
  kernel. An integer overflow in the ALIGN() function, specifically within the
  symlink_data() error context loop, can lead to an out-of-bounds read. This
  issue allows…
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 9
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-14'
sourceUpdated: '2026-09-14T19:27:16+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89634.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89634.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89634'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532080'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89634'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89634'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89634.mbox
  - url: 'https://git.kernel.org/stable/c/2b4a25baa0b936fef6915c0459925077b324ecaf'
  - url: 'https://git.kernel.org/stable/c/b89d678f9eafcf8d74885983166ba26b40a04ea0'
  - url: 'https://git.kernel.org/stable/c/657372ba6ea50b4474d2a6a610097eae8cd1f3e9'
  - url: 'https://git.kernel.org/stable/c/1f824f61d1df52392eaf0b74dfa5659d724fde30'
  - url: 'https://git.kernel.org/stable/c/62a3025983c8c735a3c6fc85a59316f31b59af07'
  - url: 'https://git.kernel.org/stable/c/62656b024efc21c3230eade1a847f25871c3d2bb'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
  - score-dispute
epss: 0.00702
epssPercentile: 0.51845
scores:
  vendor: 7
  cna: 9.1
ingestedAt: '2026-09-14T15:23:07.450Z'
---

## Overview

A flaw was found in the Server Message Block (SMB) client within the Linux kernel. An integer overflow in the ALIGN() function, specifically within the symlink_data() error context loop, can lead to an out-of-bounds read. This issue allows a malicious SMB server to cause a denial of service (DoS) by triggering an infinite loop or potentially disclose sensitive information.

## Vendor advisories

- **Red Hat VEX** · Moderate · 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 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89634.json)

**kernel: smb: client: fix ALIGN() overflow in symlink_data() error context loop** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-14.

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

Not affected:

- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat OpenShift Container Platform 4

## Remediation

Affected