---
id: CVE-2026-89604
title: 'kernel: efivarfs: Rate limit statfs() handler (CVE-2026-89604)'
summary: >-
  A flaw was found in the Linux kernel's efivarfs component. An unprivileged
  local user can exploit this by repeatedly calling the `statfs()` handler on
  the `efivarfs` mount point. This action triggers a flood of calls to the
  `QueryVariableI…
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-770
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T07:13:51+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89604.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89604.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89604'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532362'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89604'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89604'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89604.mbox
  - url: 'https://git.kernel.org/stable/c/0dbc2e94b81df5a1264068b6ed3605c654b8afcb'
  - url: 'https://git.kernel.org/stable/c/8953bdd1b9c0e748d5408d3d0b8e7aeee5c9cd41'
  - url: 'https://git.kernel.org/stable/c/92895a14329cc9533e2a74a265214f690ba3851a'
  - url: 'https://git.kernel.org/stable/c/b2326338dc683e8c1067c0cbf7a47986c4190902'
  - url: 'https://git.kernel.org/stable/c/97d71ebee48cd1b29091762b3e5cca4f815dd84c'
  - url: 'https://git.kernel.org/stable/c/3cd611c9f1dbcc116c8af5112e3c1783c8cde2ae'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00206
epssPercentile: 0.09346
ingestedAt: '2026-09-14T15:23:07.451Z'
---

## Overview

A flaw was found in the Linux kernel's efivarfs component. An unprivileged local user can exploit this by repeatedly calling the `statfs()` handler on the `efivarfs` mount point. This action triggers a flood of calls to the `QueryVariableInfo()` runtime service, which is particularly costly on x86 systems. The excessive calls can lead to significant performance degradation, potentially resulting in a Denial of Service (DoS).

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89604.json)

**kernel: efivarfs: Rate limit statfs() handler** — rated Low by Red Hat. Released 2026-09-11, updated 2026-09-16.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

No fix planned:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

Not affected:

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

## Remediation

Fix deferred