CVE-2026-33921 MEDIUM

CVE-2026-33921: Npcap driver installed without administrator-only access restriction on Windows in Arc before v2.7.0

Vendor Nozomi Networks
Product Arc
Weakness CWE-1188
Published August 11, 2026
Last update August 11, 2026

CVSS base score

4.8/10
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality
Integrity

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

August 11, 2026 CVE published