Insecure Permissions in M66B NetGuard No-Root Firewall
CVE-2026-107039

7.5HIGH

Key Information:

Vendor

M66B

Status
NetGuard no-root firewall
Vendor
CVE Published:
29 October 2026

What is CVE-2026-107039?

The ActivityMain component of M66B's NetGuard no-root firewall has a vulnerability due to insecure permissions. This flaw enables unauthorized attackers to initiate arbitrary device resets or cause a Denial of Service (DoS), compromising device functionality and user experience. Users should review their installation of the affected version, 2.337, to mitigate potential risks associated with unauthorized system access.

References

https://github.com/M66B/NetGuard
https://f-droid.org/packages/eu.faircode.netguard/
https://github.com/FFG0d/fdroid-android-advisories/blob/m...

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.