---
id: CVE-2026-111581
title: >-
  Libblockdev: libblockdev: argument injection in ntfs/vfat label-setting
  helpers via udisks2 setlabel() d-bus method
summary: >-
  A flaw was found in libblockdev. The bd_fs_ntfs_set_label() and
  bd_fs_vfat_set_label() functions pass caller-supplied label values as bare
  positional arguments to the ntfslabel and fatlabel utilities without
  end-of-options separators or …
severity: low
cvss: 3.3
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-88
vendor: Red Hat
product: libblockdev
affected:
  - libblockdev (all versions)
  - libblockdev (all versions)
  - libblockdev (all versions)
  - libblockdev (all versions)
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-16T16:32:08.637542Z'
published: '2026-10-16'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T17:06:09.524Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-111581'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-111581'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2554104'
    label: RHBZ#2554104
tags:
  - cve.org
ingestedAt: '2026-10-16T18:43:08.841Z'
---

## Overview

A flaw was found in libblockdev. The bd_fs_ntfs_set_label() and bd_fs_vfat_set_label() functions pass caller-supplied label values as bare positional arguments to the ntfslabel and fatlabel utilities without end-of-options separators or input validation for values beginning with a dash. This allows a label starting with '-' to be interpreted as a command-line flag by the spawned tool, potentially bypassing safety checks or causing unintended operations. This is reachable by unprivileged local users through the udisks2 Filesystem.SetLabel() D-Bus method without administrator authentication.

## Affected

- `libblockdev (all versions)`
- `libblockdev (all versions)`
- `libblockdev (all versions)`
- `libblockdev (all versions)`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

### Workarounds

There is no practical mitigation that does not affect normal desktop functionality. Restricting the polkit policy for org.freedesktop.udisks2.modify-device to require administrator authentication (changing allow_active from "yes" to "auth_admin") would block the attack surface but would also require a password for all legitimate filesystem label and UUID operations on user-owned devices.