# 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.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Aug 2026
- **Updated:** 11 Aug 2026
- **Also known as:** GHSA-gwvc-2mf6-9jv4

## 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 (Initialization of a Resource with an Insecure Default)

## 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33921 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-33921 in the wild and no public exploit code.

Affected product: Nozomi Networks Arc. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-33921/ (Markdown: https://insights.sbomify.com/CVE-2026-33921/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33921
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33921
- OSV: https://osv.dev/vulnerability/CVE-2026-33921

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33921/
Summaries are generated and may contain mistakes; the official description above is the record.