---
id: CVE-2026-89575
title: >-
  kernel: dm raid1: reserve space for NUL-terminator in
  build_constructor_string() (CVE-2026-89575)
summary: >-
  A flaw was found in the Linux kernel's device mapper (dm-raid1) component.
  This vulnerability occurs in the `build_constructor_string()` function, where
  insufficient space is reserved for a NUL-terminator when formatting a string
  with `spr…
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-787
  - CWE-170
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 6
  - enterprise_linux 7
  - enterprise_linux 8
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-10-24'
sourceUpdated: '2026-10-24T00:47:37+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89575.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89575.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89575'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532259'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89575'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89575'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89575.mbox
  - url: 'https://kernelcve.org/list/?q=CVE-2026-89575'
  - url: 'https://git.kernel.org/stable/c/35ba81c93fe7392c973af9881640180490e76f34'
  - url: 'https://git.kernel.org/stable/c/1fcc9f9f35653c5ee1a8b144ec96ff3fc48532f7'
  - url: 'https://git.kernel.org/stable/c/7b035983b895db3ae01d9855963d42541db42125'
  - url: 'https://git.kernel.org/stable/c/01a0276706c7b6fb758a8e2ff9cf221a3dfcae97'
  - url: 'https://git.kernel.org/stable/c/0a3657ebd6b517b60cdc5123894047616974e25b'
  - url: 'https://git.kernel.org/stable/c/644140527ae494cedf3b5c0ecd16287deaea7a66'
  - url: 'https://git.kernel.org/stable/c/f79b53ca3a68a46c6fc3b30b148d1dfb1b33ea8b'
  - url: 'https://git.kernel.org/stable/c/73c37fe54cd056d07461b142ab0b8b81e1ef6ad8'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00234
epssPercentile: 0.14221
ingestedAt: '2026-09-14T15:23:07.451Z'
---

## Overview

A flaw was found in the Linux kernel's device mapper (dm-raid1) component. This vulnerability occurs in the `build_constructor_string()` function, where insufficient space is reserved for a NUL-terminator when formatting a string with `sprintf()`. This oversight can lead to a buffer overflow, potentially allowing an attacker to cause a denial of service or execute arbitrary code.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-10-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89575.json)

**kernel: dm raid1: reserve space for NUL-terminator in build_constructor_string()** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-10-24.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

No fix planned:

- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

## Remediation

Out of support scope

Workarounds / mitigations:

- Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.