---
id: "CVE-2026-77059"
kind: "vulnerability"
aliases: ["CVE-2026-77059"]
title: "boneIO Black: race in sudoers file write enables local root escalation"
severity: "high"
cvss: 8.8
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["boneio", "infrastructure", "linux", "raspberry-pi", "self-hosted"]
not_affected_if: ["fixed-version-1.6.0-or-later"]
published_at: "2026-10-26T15:16:43+00:00"
first_seen_at: "2026-10-26T16:02:26+00:00"
updated_at: "2026-10-26T16:03:33+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77059", "first_seen_at": "2026-10-26T16:02:26+00:00"}]
---

# boneIO Black: race in sudoers file write enables local root escalation

boneIO Black writes sudoers rules to a predictable temporary file, validates them, then installs them as root, leaving a race window. A local user can swap the content or use a symlink on that filename to inject arbitrary sudoers rules and become root.

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

## How to check

- Check the installed boneIO Black version; the sources say it is fixed in `1.6.0`.
- Check whether `boneio/webui/routes/timezone_sudoers.py` exists and contains `create_timedatectl_sudoers_file()`, which the sources name as the affected function.

## Fix

- Upgrade boneIO Black to `1.6.0` or later.

## Timeline

- 2026-10-26T16:02:26+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-77059

## From the sources

boneIO Black contains a TOCTOU race condition in the create_timedatectl_sudoers_file() function in boneio/webui/routes/timezone_sudoers.py. The function writes sudoers rules to a predictable temporary file, validates them, then installs them with root privileges. A local attacker can exploit the race window between validation and installation to substitute malicious content, or use the predictable filename for symlink attacks, resulting in arbitrary sudoers rule injection and local privilege escalation to root.

This issue was fixed in version 1.6.0.

---

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