Insecure permissions in the ActivityMain component of M66B/Marcel Bokhorst NetGuard no-root firewall versionCode 2026080101/versionName…
Affects NetGuard version 2026080101 (versionName 2.337) for Android. No fixed version is listed in the checked facts.
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Default setups
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: poc
- Automatable: yes
- Technical impact: partial
Summary
NetGuard, an Android no-root firewall app developed by Marcel Bokhorst (M66B), contains insecure permissions in its ActivityMain component. An unauthorized attacker could use this flaw to force a device reset or cause a denial of service.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original 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).
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: poc · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
No affected packages have been listed by the sources.
References 3
GitHub · M66B/NetGuard
f-droid.org
GitHub · FFG0d/fdroid-android-advisories
Questions about CVE-2026-107039
What does this mean?
The ActivityMain component can be reached by a zero-permission app that sends an extra named Approve, which switches NetGuard's firewall off by stopping its VPN service. The change persists across force-stop and reboot. The advisory measured no traffic-level, per-app-rule or confidentiality effect.Source: github.com
Am I affected, and how do I check?
The affected build is NetGuard (eu.faircode.netguard) version 2026080101, versionName 2.337. Turning the firewall back on through this path additionally requires that the one-time VPN consent already exists. To check an installed copy, compare its versionCode and versionName with 2026080101 and 2.337 in the Android app details.Source: github.com
What should I do about it?
The checked facts do not name a fixed version, so no upgrade target can be given. Check the NetGuard release notes or the advisory for a patched build.Source: github.com
Is it being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. CISA's SSVC assessment notes a proof of concept exists. No public exploit code is tracked.Source: cve.now feed data
What if there's no patch?
The checked facts list no workaround. The only documented limit is that the enable direction needs an existing VPN consent.Source: github.com