CVE-2026-33921

Local packet capture and injection via unrestricted Npcap

Published Aug 11, 2026 · Updated Aug 11, 2026

Insecure Npcap access in Nozomi Networks Arc before 2.7.0 allows local users to capture traffic and inject raw packets on Windows. Arc's Windows installer leaves Npcap's /admin_only option disabled, so capture devices receive ACLs that permit non-administrator access. Any local low-privilege account can read host and same-segment traffic and transmit arbitrary raw packets, with no user interaction.

CVSS severity4.8
Medium
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insecure Npcap access in Nozomi Networks Arc before 2.7.0 allows local users to capture traffic and inject raw packets on Windows. Arc's Windows installer leaves Npcap's /admin_only option disabled, so capture devices receive ACLs that permit non-administrator access. Any local low-privilege account can read host and same-segment traffic and transmit arbitrary raw packets, with no user interaction.

The record

CVE
CVE-2026-33921
Published
Aug 11, 2026
Updated
Aug 11, 2026
Vendor
Nozomi Networks
Product
Arc
Classifications
CWE-1188, T1040
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <2.7.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Nozomi Networks · Arcversion=0 <2.7.0

Published CVSS scores

5.2Nozomi NetworksCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
4.8Nozomi NetworksCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1188Initialization of a Resource with an Insecure Default
T1040Network Sniffing

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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