---
id: CVE-2026-43391
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nsfs: tighten permission checks for handle opening

  Even privileged services should not necessarily be able to see other
  privileged service's namespaces so they can't l…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nsfs: tighten permission checks for handle opening

  Even privileged services should not necessarily be able to see other
  privileged service's namespaces so they can't l…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 6.18, < 6.19.9'
  - linux_kernel = 7.0
patched:
  - linux_kernel 6.19.9
published: '2026-05-08'
updated: '2026-09-07'
sourceUpdated: '2026-09-07T16:17:28.400'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-43391'
references:
  - url: 'https://git.kernel.org/stable/c/1797ee11451f1b2be69863a9f5bd43b948813fdf'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/24ebaf6676ae4f74f4856eb645959b15e62bc1b4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d2324a9317f00013facb0ba00b00440e19d2af5e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00128
epssPercentile: 0.02778
ingestedAt: '2026-09-07T17:14:51.618Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

nsfs: tighten permission checks for handle opening

Even privileged services should not necessarily be able to see other
privileged service's namespaces so they can't leak information to each
other. Use may_see_all_namespaces() helper that centralizes this policy
until the nstree adapts.

## Affected

- `linux_kernel >= 6.18, < 6.19.9`
- `linux_kernel = 7.0`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.19.9`