CVE-2026-33921 Npcap driver installed without administrator-only access restriction on Windows in Arc before v2.7.0
Local users can capture network traffic and send raw packets due to insecure Npcap driver permissions in Arc installer.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-33921?
CVE-2026-33921 is a medium-severity vulnerability in Nozomi Networks Arc, published on 11 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
The Windows installer deployed Npcap leaving its access restriction option at the insecure default value, so the driver was accessible to every local user of the host instead of being restricted to administrators only. A local user without administrative privileges could use the Npcap driver to capture the traffic reaching the host, which discloses information belonging both to the host and to other systems on the same network segment, and to send arbitrary raw packets on that segment.
Weakness: CWE-1188
Which versions are affected by CVE-2026-33921?
How do I fix CVE-2026-33921?
No fix has been published for CVE-2026-33921 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-33921 being exploited?
There is no known exploitation of CVE-2026-33921 in the wild and no public exploit code.
Sources
Also known as GHSA-gwvc-2mf6-9jv4.