CVE-2026-4252Public exploitNetwork attack vector

Unauthenticated handler access via IPv6 substring match

Published Mar 16, 2026 · Updated Mar 16, 2026

Improper authentication in Tenda AC8 16.03.50.11 allows remote attackers to access administrative handlers over LAN IPv6. R7WebsSecurityHandler skips normal authentication for IPv6 clients, then uses strstr on the full URL to permit requests containing goform/ and fast_setting_wifi_set. Access to the same network segment and the router's IPv6 link-local address is required; reachable handlers can alter Wi-Fi settings or enable Telnet without credentials.

CVSS severity9.8
Critical
EPSS probability1.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper authentication in Tenda AC8 16.03.50.11 allows remote attackers to access administrative handlers over LAN IPv6. R7WebsSecurityHandler skips normal authentication for IPv6 clients, then uses strstr on the full URL to permit requests containing goform/ and fast_setting_wifi_set. Access to the same network segment and the router's IPv6 link-local address is required; reachable handlers can alter Wi-Fi settings or enable Telnet without credentials.

The record

CVE
CVE-2026-4252
Published
Mar 16, 2026
Updated
Mar 16, 2026
Vendor
Shenzhen Tenda Technology Co., Ltd.
Product
AC8
Classifications
CWE-291, CWE-287, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=16.03.50.11

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Shenzhen Tenda Technology Co., Ltd. · AC8version=16.03.50.11

Published CVSS scores

8.9VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
10.0VulDBAV:N/AC:L/Au:N/C:C/I:C/A:C
9.8VulDBCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-291Reliance on IP Address for Authentication
CWE-287Improper Authentication
T1210Exploitation of Remote Services

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo