---
id: CVE-2026-89765
title: >-
  kernel: timers/itimer: Zero-init old itimerval before copy to userspace
  (CVE-2026-89765)
summary: >-
  A flaw was found in the Linux kernel's `timers/itimer` component. On native
  sparc64 systems, the `struct __kernel_old_timeval` contains uninitialized
  padding bytes. When `put_itimerval()` copies this structure to userspace,
  these padding b…
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-201
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: '2026-09-21'
sourceUpdated: '2026-09-21T18:32:05+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89765.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89765.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89765'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532295'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89765'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89765'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89765.mbox
  - url: 'https://git.kernel.org/stable/c/00ef529a5402f41eb1d227916437e237450719f9'
  - url: 'https://git.kernel.org/stable/c/18c7d85864e554adc8fad1e8d2e9d2cb6c3911c8'
  - url: 'https://git.kernel.org/stable/c/2bf5e8f7c9bf4ad3be343a9a6e3e50a34264d25e'
  - url: 'https://git.kernel.org/stable/c/4c66719dd1e4023c5e3f7d050f1bbefec3dfbeb4'
  - url: 'https://git.kernel.org/stable/c/6d4b937251386d9c6f968e7802f0cb16a8523772'
  - url: 'https://git.kernel.org/stable/c/4ea70146ab9376092297eb8b622ef1792797f2cf'
  - url: 'https://git.kernel.org/stable/c/a17b345daff46fec4af9f1ecbdf350208016dd15'
  - url: 'https://git.kernel.org/stable/c/bdfda99c5763822a9a888e8af0ad7d9312ffcfe2'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00196
epssPercentile: 0.09597
ingestedAt: '2026-09-14T15:23:07.448Z'
---

## Overview

A flaw was found in the Linux kernel's `timers/itimer` component. On native sparc64 systems, the `struct __kernel_old_timeval` contains uninitialized padding bytes. When `put_itimerval()` copies this structure to userspace, these padding bytes can be exposed, leading to information disclosure. This vulnerability allows a local attacker to potentially read sensitive kernel memory.

## Vendor advisories

- **Red Hat VEX** · Low · 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 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89765.json)

**kernel: timers/itimer: Zero-init old itimerval before copy to userspace** — rated Low by Red Hat. Released 2026-09-11, updated 2026-09-21.

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

Fix deferred