---
id: "CVE-2026-111581"
kind: "vulnerability"
aliases: ["CVE-2026-111581"]
title: "libblockdev: filesystem label flags let local users pass options to ntfslabel and fatlabel"
severity: "low"
cvss: 3.3
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["desktop", "infrastructure", "libblockdev", "linux", "servers-with-udisks2", "udisks2"]
not_affected_if: ["no-local-users", "no-udisks2"]
published_at: "2026-10-16T16:17:04+00:00"
first_seen_at: "2026-10-23T21:57:13+00:00"
updated_at: "2026-10-25T04:47:16+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-111581", "first_seen_at": "2026-10-23T21:57:13+00:00"}]
---

# libblockdev: filesystem label flags let local users pass options to ntfslabel and fatlabel

libblockdev passes filesystem label values to the ntfslabel and fatlabel tools without stopping option parsing, so a label starting with a dash is read as a command-line flag. Unprivileged local users can reach this through the udisks2 Filesystem.SetLabel() D-Bus method without administrator authentication.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- unknown

## Fix

- unknown

## Timeline

- 2026-10-23T21:57:13+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-111581

## From the sources

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.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_