VulnerabilityPublished 15 Mar 2026Updated 17 Mar 2026

CVE-2026-4180: D-Link DIR-816 · Improper Access Controls

Affects D-Link DIR-816Source CVE Database V5

Public exploit available · CVSS 6.9 Medium · end of life, no fix coming : replace or isolate D-Link DIR-816; no fix will be released.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 4.0 base score

6.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 1.3% chance of exploitation in 30 days – higher than 72% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: None coming – the product is end of life

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

Base metrics

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: Low
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Threat metrics

Exploit Maturity: POC

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

No fix will be released: D-Link DIR-816 is end of life. Replace it, or isolate it from untrusted networks until you can.

Affected software

Product	Affected	Fixed in
D-LinkDIR-816	Affected =1.10CNB05	Fixed in–

AI-suggested

Immediately discontinue use of the D-Link DIR-816 router running firmware 1.10CNB05, as it is no longer supported and vulnerable. Replace it with a currently supported device that receives regular security updates.
If replacement is not immediately feasible, disable all remote management and administration interfaces accessible from untrusted networks to reduce exposure.
Segment the network to isolate the vulnerable router from critical systems and sensitive data to limit potential impact.
Monitor network traffic for unusual activity that may indicate exploitation attempts targeting the redirect.asp endpoint or token_id parameter.
Employ network-level protections such as firewalls and intrusion detection/prevention systems to block unauthorized access attempts.
Educate users and administrators about the risks of using unsupported hardware and the importance of timely device replacement.
Regularly audit network devices to identify unsupported or vulnerable equipment and prioritize their upgrade or decommissioning.
Consider deploying network access control (NAC) solutions to enforce device compliance and restrict vulnerable devices from critical network segments.

Description

CVE-2026-4180 is a medium severity vulnerability affecting the D-Link DIR-816 router running firmware version 1.10CNB05. It involves improper access controls in the redirect.asp component, specifically through manipulation of the token_id argument. The flaw allows remote attackers to bypass access restrictions without authentication or user interaction. Although the exploit code is publicly available, the affected product is no longer supported by the vendor, and no known exploits are currently observed in the wild. The vulnerability could lead to unauthorized access or control over the device, impacting confidentiality, integrity, and availability. Organizations using this outdated router model are at risk and should consider mitigation steps. Due to the product’s market presence, countries with significant consumer or enterprise deployment of D-Link devices are more likely to be affected. Immediate mitigation involves network segmentation, disabling remote management, and replacing unsupported hardware.

Impact

The improper access control vulnerability in the D-Link DIR-816 router can lead to unauthorized remote access to device functions, potentially allowing attackers to alter configurations, intercept or redirect network traffic, or disrupt device availability. This compromises the confidentiality, integrity, and availability of the affected device and any networks relying on it. Since the device is often deployed in home and small office environments, exploitation could lead to network compromise, data interception, or use of the device as a pivot point for further attacks. The lack of vendor support means no patches will be released, increasing the risk of exploitation over time. Organizations using this router model may face increased exposure to attacks, especially if remote management is enabled or the device is accessible from untrusted networks. The exploit’s public availability further raises the likelihood of opportunistic attacks. While no known exploits in the wild are reported yet, the vulnerability’s characteristics make it a credible threat to affected users.

Summary

CVE-2026-4180 identifies an improper access control vulnerability in the D-Link DIR-816 router, specifically in firmware version 1.10CNB05. The vulnerability resides in an unknown function within the redirect.asp file of the goahead web server component embedded in the device. By manipulating the token_id parameter, an attacker can bypass intended access controls remotely without requiring authentication or user interaction. This allows unauthorized users to potentially access restricted functions or sensitive information on the router. The vulnerability has a CVSS 4.0 base score of 6.9, indicating a medium severity level, with an attack vector of network (remote), low attack complexity, and no privileges or user interaction needed. Although the exploit is publicly available, the product is no longer supported by D-Link, meaning no official patches or updates are forthcoming. The lack of vendor support increases risk as vulnerabilities remain unpatched. The goahead web server is commonly used in embedded devices, and the redirect.asp script likely handles HTTP redirection or session management, making improper token validation critical. The vulnerability could be leveraged to gain unauthorized control or disrupt device operation, potentially impacting network security and device availability.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 24 Mar 2026, 01:03 UTC

Technical details

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