VulnerabilityPublished 15 Mar 2026

CVE-2026-4193: D-Link DIR-823G · Improper Access Controls

Affects D-Link DIR-823GSource CVE Database V5

Public exploit available · CVSS 6.9 Medium · end of life, no fix coming : replace or isolate D-Link DIR-823G; 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: 0.7% chance of exploitation in 30 days – higher than 55% 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-823G is end of life. Replace it, or isolate it from untrusted networks until you can.

Affected software

Product	Affected	Fixed in
D-LinkDIR-823G	Affected =1.0.2B05	Fixed in–

AI-suggested

Given the absence of official patches for this unsupported firmware version, organizations should prioritize replacing the affected D-Link DIR-823G devices with newer, supported models that receive regular security updates. If immediate replacement is not feasible, network administrators should implement strict network segmentation to isolate these routers from untrusted networks, especially the internet, to reduce exposure. Disable remote management interfaces or restrict access to trusted IP addresses only. Employ network-level access controls such as firewalls to block unauthorized inbound traffic targeting router management ports. Regularly audit router configurations and logs for unauthorized changes or suspicious activity. Consider deploying intrusion detection/prevention systems (IDS/IPS) to monitor for exploitation attempts. Educate users and administrators about the risks of using unsupported hardware and the importance of timely device upgrades. Finally, maintain an inventory of all network devices to identify and track vulnerable equipment proactively.

Description

CVE-2026-4193 is a medium-severity vulnerability affecting the D-Link DIR-823G router version 1.0.2B05. It involves improper access controls in multiple functions of the goahead component, allowing remote attackers to manipulate critical router settings without authentication or user interaction. The vulnerability impacts various configuration functions such as DDNS, firewall, guest network, LAN/WAN settings, and more. Although the product is no longer supported and no patches are available, the exploit has been publicly disclosed, increasing the risk of exploitation. The CVSS 4.0 score is 6.9, reflecting the ease of remote exploitation and the potential for confidentiality, integrity, and availability impacts. Organizations using this router model remain at risk, especially if devices are exposed to untrusted networks.

Impact

The improper access control vulnerability in D-Link DIR-823G routers can have significant impacts on affected organizations. Attackers can remotely manipulate router configurations, potentially leading to unauthorized changes in network topology, firewall rules, and access control lists. This can result in network traffic interception, unauthorized access to internal resources, disruption of network services, and exposure of sensitive information. The ability to alter guest network settings and firewall configurations can facilitate lateral movement within networks or create backdoors for persistent access. Since the device is a network gateway, compromise can affect the confidentiality, integrity, and availability of the entire network segment it serves. The lack of vendor support and patches exacerbates the risk, as vulnerable devices remain exposed indefinitely. Organizations relying on these routers in critical environments or with internet-facing management interfaces are particularly at risk. The medium severity rating indicates a moderate but tangible threat that requires attention to prevent exploitation.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 23 Mar 2026, 00:43 UTC

Technical details

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