CVE-2026-107039 Details
Description
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).
A vulnerability in the ActivityMain component of M66B NetGuard no-root firewall, specifically in version 2026080101, has been identified. This vulnerability arises from insecure permissions that allow unauthorized attackers to arbitrarily force a device reset or cause a denial-of-service condition. The issue is rooted in an exported, permission-less activity that misinterprets the name of a boolean extra as user approval, enabling any app with no permissions to silently disable the firewall and disrupt the VPN service, without any user interaction or notification.
As of September 27, 2026, no fix has been released for this vulnerability. However, it is recommended to add a permission requirement to the affected component or to set the component as not exported, restricting access to only the vendor's applications.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Oct 29, 2026CISA-ADP
Assessed Oct 30, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/FFG0d/fdroid-android-advisories/blob/main/advisories/CVE-2026-107039.md | CISA-ADP | AdvisoryExploitRemedy |
| https://f-droid.org/packages/eu.faircode.netguard/ | [email protected] | ProductVendor |
| https://github.com/FFG0d/fdroid-android-advisories/blob/main/advisories/CVE-2026-107039.md | [email protected] | AdvisoryExploitRemedy |
| https://github.com/M66B/NetGuard | [email protected] | ProductVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-732 | Incorrect Permission Assignment for Critical Resource | CISA-ADP |
Affected Products
| Product | Versions |
|---|---|
| Marcel Bokhorst NetGuard | 2026080101 |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Oct 30, 2026 | CVE Modified | CISA-ADP |
| Oct 29, 2026 | New CVE Received | [email protected] |