---
id: CVE-2026-89728
title: >-
  kernel: i3c: renesas: Fix out-of-bounds access for newdevs mask
  (CVE-2026-89728)
summary: >-
  A flaw was found in the Linux kernel's I3C Renesas driver. When the I3C bus is
  empty and software initiates Dynamic Address Assignment (DAA), an
  out-of-bounds access can occur. This is due to an incorrect calculation of the
  newly discovere…
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-805
vendor: Red Hat
product: Red Hat OpenShift Container Platform 4
affected:
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-15'
sourceUpdated: '2026-09-15T14:06:02+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89728.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89728.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89728'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532480'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89728'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89728'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89728.mbox
  - url: 'https://git.kernel.org/stable/c/769f5a233efcf8587f70fb2244a202d88582c746'
  - url: 'https://git.kernel.org/stable/c/50dec95c9d1f1f82819bc898ef2b60fa83fd4ccd'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00156
epssPercentile: 0.05134
ingestedAt: '2026-09-14T11:11:19.885Z'
---

## Overview

A flaw was found in the Linux kernel's I3C Renesas driver. When the I3C bus is empty and software initiates Dynamic Address Assignment (DAA), an out-of-bounds access can occur. This is due to an incorrect calculation of the newly discovered devices bitmask, which can lead to system instability or other undefined behavior.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat OpenShift Container Platform 4 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89728.json)

**kernel: i3c: renesas: Fix out-of-bounds access for newdevs mask** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-15.

Affected:

- Red Hat OpenShift Container Platform 4

No fix planned:

- Red Hat OpenShift Container Platform 4

## Remediation

Fix deferred