What is the CVSS score of CVE-2026-4183?

CVE-2026-4183 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Is there a public PoC exploit available for CVE-2026-4183?

Yes, a public proof-of-concept exploit is available for CVE-2026-4183. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2026-4183?

Within 24 hours: Identify and inventory all D-Link DIR-816 devices on your network; isolate affected devices from critical systems if replacement is not immediately possible. Within 7 days: Procure replacement routers from a vendor with active security support; begin staged replacement of affected devices. Within 30 days: Complete replacement of all DIR-816 units and retire from active use; verify network baseline and conduct security assessments post-replacement.

Dir 816 CVE-2026-4183

EUVD-2026-12238 CRITICAL

Stack-based Buffer Overflow (CWE-121)

2026-03-15 VulDB

Buffer Overflow D-Link Stack Overflow Dir 816 D-Link

9.8

CVSS 3.1 · NVD

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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Send crafted HTTP request to /goform/form2WlanBasicSetup.cgi
Exploit

Supply oversized pskValue parameter
Execution

Trigger stack-based buffer overflow
Impact

Execute arbitrary code on device

Vulnerability Assessment

Weakness	CWE CWE-121 OWASP Top 10:2025 A06:2021 - Vulnerable and Outdated Components ASVS 5.0 V15 - Secure Coding and Architecture Stack buffer bounds checking MITRE ATT&CK 1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Exploitation Conditions	D-Link DIR-816 firmware version 1.10CNB05 with goahead web server enabled and /goform/form2WlanBasicSetup.cgi endpoint accessible. No authentication required; exploitable via unauthenticated remote HTTP requests against default router configuration.
Impact	This vulnerability presents extremely high real-world risk. The CVSS 3.1 score of 9.8 accurately reflects the severity: network-accessible (AV:N), low complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), with complete compromise of confidentiality, integrity, and availability. The exploit is marked as 'Proof-of-Concept' (E:P) in the CVSS vector and publicly available on GitHub. While no EPSS score or KEV listing is mentioned, the combination of unauthenticated remote exploitation, public POC availability, and affecting consumer routers makes this a priority threat. The only mitigating factor is that affected devices are end-of-life, potentially limiting the installed base.
Exploit ScenarioDerived	An attacker can exploit this vulnerability by sending a specially crafted HTTP POST request to the router's web interface at /goform/form2WlanBasicSetup.cgi with an oversized pskValue parameter. No authentication is required, and the attack can be launched from anywhere on the internet if the router's management interface is exposed. The proof-of-concept code available at https://github.com/wudipjq/my_vuln/blob/main/D-Link7/vuln_87/87.md demonstrates the attack. Successful exploitation grants the attacker complete control over the router, enabling traffic interception, DNS hijacking, and pivoting into the internal network.

Act Now Prioritize within 24-48h. Why: CRITICAL severity + public POC available.

No patch listed yet 0.1% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 15, 2026

Critical stack-based buffer overflow vulnerability in D-Link DIR-816 router firmware version 1.10CNB05, affecting the wireless configuration interface (/goform/form2WlanBasicSetup.cgi). A publicly available proof-of-concept exploit exists, allowing remote attackers without authentication to achieve complete system compromise. The vulnerability affects end-of-life products no longer supported by D-Link, making patches unlikely.

RemediationAI

No patches are available as D-Link has discontinued support for the DIR-816 router series. The only effective remediation is to replace affected devices with currently supported router models. As an interim mitigation, administrators should: 1) Disable remote management features if enabled, 2) Restrict access to the web management interface to trusted IP addresses only via firewall rules, 3) Monitor for suspicious access to /goform/form2WlanBasicSetup.cgi in web server logs. Given the end-of-life status, immediate replacement is strongly recommended.

Affected VersionsENISA

DIR-816 1.10CNB05

Affected Packages

euvd dir_816 no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

The vulnerability resides in the GoAhead embedded web server component, specifically in the form2WlanBasicSetup.cgi file that handles wireless network configuration. The flaw is a classic stack-based buffer overflow (CWE-121) where the pskValue parameter (likely the WPA/WPA2 pre-shared key field) is not properly bounds-checked before being copied to a fixed-size stack buffer. Based on the CPE string (cpe:2.3:a:d-link:dir-816:*:*:*:*:*:*:*:*), all versions of the DIR-816 router may be affected, though only version 1.10CNB05 is confirmed vulnerable.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

PoC Detected

Mar 16, 2026 - 14:53 vuln.today

Public exploit code

CVE Published

Mar 15, 2026 - 16:32 nvd

CRITICAL 9.8

DescriptionCVE.org

A security vulnerability has been detected in D-Link DIR-816 1.10CNB05. Affected is an unknown function of the file /goform/form2WlanBasicSetup.cgi of the component goahead. Such manipulation of the argument pskValue leads to stack-based buffer overflow. The attack can be executed remotely. The exploit has been disclosed publicly and may be used. This vulnerability only affects products that are no longer supported by the maintainer.

Executive ViewAI

Why It Matters

A critical remote code execution vulnerability (CVSS 9.8) affects D-Link DIR-816 routers running firmware 1.10CNB05, with public exploits now available. Any organization using this unsupported end-of-life device faces immediate risk of complete network compromise, as attackers can execute arbitrary code without authentication.

Business Impact: Severe

Compensating Controls

Implement network segmentation to restrict device access to trusted networks only; deploy WAF rules to block requests to /goform/form2WlanBasicSetup.cgi; disable remote management features if available; restrict administrative access to device management interfaces via IP allowlisting; monitor for suspicious outbound connections; consider upgrading to vendor-supported equipment as the primary mitigation strategy.

Threat Intelligence Overview

EPSS Score

0.1%

Top 81% exploitable

Exploit

POC

Public exploit code exists

Data Quality

6 sources

Confidence: High

EUVD

NVD

CVE.org

EPSS

GitHub

VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity CRITICAL

CISA KEV No

Public POC Yes

EPSS 0.1%

Patch available No

Active threat No

Deciding rule

CRITICAL severity + public POC available

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Out-of-Cycle

Exploitation· derived

Poc

System Exposure· derived

Open

Automatable· derived

Yes

Human Impact

Very High

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +49

PoC: +20

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Buffer Overflow HIGH

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Stack-based Buffer Overflow HIGH

A stack-based buffer overflow occurs when a program writes more data to a buffer located on the stack than it was allocated to hold.