---
id: CVE-2026-33921
title: >-
  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
summary: >-
  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
  witho…
severity: medium
cvss: 5.2
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N'
cwe:
  - CWE-1188
published: '2026-08-11'
updated: '2026-08-28'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-33921'
references:
  - url: 'https://security.nozominetworks.com/NN-2026:14-01'
    label: prodsec@nozominetworks.com
tags:
  - nvd
epss: 0.00133
epssPercentile: 0.0234
ingestedAt: '2026-08-29T18:40:35.988Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.