Which versions of Dir 816 are affected by CVE-2026-4180?

D-Link DIR-816 routers running firmware 1.10CNB05 contain a publicly exploitable access control vulnerability that allows unauthenticated remote attackers to bypass authentication via parameter…

Is there a public PoC exploit available for CVE-2026-4180?

Yes, a public proof-of-concept exploit is available for CVE-2026-4180. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-4180?

Within 24 hours: Inventory all D-Link DIR-816 devices in production and isolate any affected units from critical networks; document current firmware versions and network topology. Within 7 days: Replace affected routers with supported alternatives from the vendor or evaluate network architecture to eliminate dependency on this unsupported device; if replacement is impossible, implement network segmentation to restrict access to the device's web interface. Within 30 days: Complete full device replacement or retirement; conduct access logs review for any signs of prior exploitation.

Dir 816 CVE-2026-4180

Q: What is the CVSS score of CVE-2026-4180?

CVE-2026-4180 has a CVSS 4.0 base score of 5.5 (Medium). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

EUVD-2026-12231 MEDIUM

Improper Access Control (CWE-284)

2026-03-15 VulDB

Authentication Bypass D-Link Dir 816 D-Link

5.5

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

5.5 MEDIUM

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Severity Changed

Apr 29, 2026 - 01:11 NVD

HIGH MEDIUM

CVSS changed

Apr 29, 2026 - 01:11 NVD

7.3 (HIGH) 5.5 (MEDIUM)

PoC Detected

Mar 16, 2026 - 14:53 vuln.today

Public exploit code

EUVD ID Assigned

Mar 15, 2026 - 14:00 euvd

EUVD-2026-12231

Analysis Generated

Mar 15, 2026 - 14:00 vuln.today

CVE Published

Mar 15, 2026 - 13:32 nvd

HIGH 7.3

DescriptionCVE.org

A vulnerability was identified in D-Link DIR-816 1.10CNB05. The impacted element is an unknown function of the file redirect.asp of the component goahead. The manipulation of the argument token_id leads to improper access controls. The attack may be initiated remotely. The exploit is publicly available and might be used. This vulnerability only affects products that are no longer supported by the maintainer.

AnalysisAI

CVE-2026-4180 is an authentication bypass vulnerability in the D-Link DIR-816 router (version 1.10CNB05) affecting the redirect.asp file in the goahead component, allowing remote attackers to gain unauthorized access without authentication. A public proof-of-concept exploit is available and the affected product is no longer supported by D-Link, making this vulnerability permanently unpatched.

Technical ContextAI

The vulnerability exists in the goahead web server component used by the D-Link DIR-816 router (CPE: cpe:2.3:a:d-link:dir-816:*:*:*:*:*:*:*:*). The flaw is classified as CWE-284 (Improper Access Control), specifically involving improper handling of the 'token_id' parameter in redirect.asp. This allows attackers to bypass authentication mechanisms that should protect administrative or restricted functionality. The goahead web server is commonly used in embedded devices and IoT products for lightweight HTTP serving.

RemediationAI

No patch is available as the D-Link DIR-816 is no longer supported by the manufacturer. Immediate remediation requires replacing affected devices with currently supported router models. As a temporary mitigation, organizations should: 1) Restrict network access to the device's management interface using firewall rules, 2) Disable remote management features if possible, 3) Monitor for suspicious access attempts to redirect.asp. The D-Link website (https://www.dlink.com/) should be consulted for recommended replacement products.