---
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: 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-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: '2026-09-18'
sourceUpdated: '2026-09-18T22:07:37+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://git.kernel.org/stable/c/0a3657ebd6b517b60cdc5123894047616974e25b'
  - url: 'https://git.kernel.org/stable/c/644140527ae494cedf3b5c0ecd16287deaea7a66'
  - url: 'https://git.kernel.org/stable/c/73c37fe54cd056d07461b142ab0b8b81e1ef6ad8'
  - url: 'https://git.kernel.org/stable/c/f79b53ca3a68a46c6fc3b30b148d1dfb1b33ea8b'
  - 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'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00238
epssPercentile: 0.13137
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 2026-09-18 · [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 2026-09-18.

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