CVE-2026-3704Public exploitNetwork attack vector

Authenticated command execution via semicolon filter bypass

Published Mar 8, 2026 · Updated Mar 8, 2026

Command injection in Wavlink WL-NU516U1 firmware 251208 allows remote authenticated users to execute commands through firewall.cgi. The DMZ handler embeds dmz_flag in a uci shell command after sub_405B2C rejects several metacharacters but fails to reject semicolons. A valid session cookie and access to the management interface are required; injected commands execute as root on the appliance.

CVSS severity7.2
High
EPSS probability4.90%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in Wavlink WL-NU516U1 firmware 251208 allows remote authenticated users to execute commands through firewall.cgi. The DMZ handler embeds dmz_flag in a uci shell command after sub_405B2C rejects several metacharacters but fails to reject semicolons. A valid session cookie and access to the management interface are required; injected commands execute as root on the appliance.

The record

CVE
CVE-2026-3704
Published
Mar 8, 2026
Updated
Mar 8, 2026
Vendor
Wavlink
Product
WL-NU516U1
Classifications
CWE-74, CWE-77, T1059.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 8, 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=251208

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Wavlink · WL-NU516U1version=251208

Published CVSS scores

7.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
2.0VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
4.7VulDBCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L
5.8VulDBAV:N/AC:L/Au:M/C:P/I:P/A:P

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
T1059.004Unix Shell

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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