---
id: CVE-2026-107039
title: >-
  Insecure permissions in the ActivityMain component of M66B/Marcel Bokhorst
  NetGuard no-root firewall versionCode 2026080101/versionName 2.337 allows
  unauthorized attackers to arbitrarily force a device reset or Denial of
  Service (DoS).
summary: >-
  Insecure permissions in the ActivityMain component of M66B/Marcel Bokhorst
  NetGuard no-root firewall versionCode 2026080101/versionName 2.337 allows
  unauthorized attackers to arbitrarily force a device reset or Denial of
  Service (DoS).
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: adp
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-30T18:01:58.732669Z'
exploitAvailable: true
published: '2026-10-29'
updated: '2026-10-30'
sourceUpdated: '2026-10-30T18:38:24.152Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-107039'
references:
  - url: 'https://github.com/M66B/NetGuard'
  - url: 'https://f-droid.org/packages/eu.faircode.netguard/'
  - url: >-
      https://github.com/FFG0d/fdroid-android-advisories/blob/main/advisories/CVE-2026-107039.md
tags:
  - cve.org
  - exploit-available
epss: 0.00488
epssPercentile: 0.42227
ingestedAt: '2026-11-05T16:24:31.339Z'
---

## Overview

Insecure permissions in the ActivityMain component of M66B/Marcel Bokhorst NetGuard no-root firewall versionCode 2026080101/versionName 2.337 allows unauthorized attackers to arbitrarily force a device reset or Denial of Service (DoS).

## Remediation

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