---
id: CVE-2026-98838
title: >-
  kernel: vt: skip screen update for DEC alignment test on backgroup consoles
  (CVE-2026-98838)
summary: >-
  A flaw was found in the Linux kernel's virtual terminal subsystem. When
  handling screen updates for background consoles, the kernel fails to properly
  verify that a console is active before redrawing it with modified font
  dimensions. A loca…
severity: medium
cvss: 4.4
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe: CWE-125
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 7
  - enterprise_linux 8
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-10-18'
updated: '2026-10-23'
sourceUpdated: '2026-10-23T21:49:00+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98838.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98838.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98838'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2555252'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98838'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98838'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98838.mbox
  - url: 'https://git.kernel.org/stable/c/2fc4e71aefab57c80ccc9775aad2af503fc90810'
  - url: 'https://git.kernel.org/stable/c/985c000b046ca4ee11ee34ef85db500c569ef6e8'
  - url: 'https://git.kernel.org/stable/c/ad06f7312d3f615dd466483ce81a9b9619166686'
  - url: 'https://git.kernel.org/stable/c/0ee53081425a1a31ce15089012cd96b8353eb44e'
  - url: 'https://git.kernel.org/stable/c/0928ed9bd7946baee911efa401088697836e3b1e'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00168
epssPercentile: 0.05973
ingestedAt: '2026-10-18T16:47:32.468Z'
---

## Overview

A flaw was found in the Linux kernel's virtual terminal subsystem. When handling screen updates for background consoles, the kernel fails to properly verify that a console is active before redrawing it with modified font dimensions. A local attacker can exploit this issue by altering font settings and issuing control sequences to an inactive console, triggering an out-of-bounds memory read against an unresized buffer. This can lead to a system crash, resulting in a Denial of Service (DoS), or potentially expose sensitive kernel memory.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: 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 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, … · updated 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98838.json)

**kernel: vt: skip screen update for DEC alignment test on backgroup consoles** — rated Moderate by Red Hat. Released 2026-10-18, updated 2026-10-23.

Affected:

- 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

No fix planned:

- 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

Not affected:

- Red Hat Enterprise Linux 6

## Remediation

Fix deferred