VulnerabilityPublished 15 Mar 2026

CVE-2026-4196: D-Link DNS-120 · Command Injection

Affects D-Link DNS-120Source CVE Database V5

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Public exploit available · CVSS 5.3 Medium.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 4.0 base score

5.3Medium

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

EPSS: 4.1% chance of exploitation in 30 days – higher than 90% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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: Low
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: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
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

Affected software

Product	Affected	Fixed in
D-LinkDNS-120	Affected =20260205	Fixed in–
D-LinkDNR-202L	Affected =20260205	Fixed in–
D-LinkDNS-315L	Affected =20260205	Fixed in–
D-LinkDNS-320	Affected =20260205	Fixed in–
D-LinkDNS-320L	Affected =20260205	Fixed in–
D-LinkDNS-320LW	Affected =20260205	Fixed in–

AI-suggested

To mitigate CVE-2026-4196, organizations should implement the following specific actions: 1) Immediately restrict network access to the affected NAS devices, especially blocking external internet access to management and backup-related CGI endpoints. 2) Disable remote backup and scheduling features (cgi_recovery, cgi_backup_now, cgi_set_schedule, cgi_set_rsync_server) if they are not essential to operations. 3) Employ network segmentation and firewall rules to isolate NAS devices from untrusted networks and limit access to trusted administrators only. 4) Monitor network traffic and device logs for unusual commands or access patterns targeting the /cgi-bin/remote_backup.cgi script. 5) Engage with D-Link support or official channels to obtain firmware updates or patches addressing this vulnerability as soon as they become available. 6) Consider deploying intrusion detection/prevention systems (IDS/IPS) with signatures for command injection attempts targeting these devices. 7) Educate IT staff about the risks of exposed NAS devices and enforce strong administrative access controls. 8) If patching is delayed, consider temporary replacement or removal of vulnerable devices from critical network segments to reduce exposure.

Description

CVE-2026-4196 is a command injection vulnerability affecting multiple D-Link network-attached storage (NAS) devices, including the DNS-120 and several other models. The flaw exists in the /cgi-bin/remote_backup.cgi script, specifically in functions handling remote backup and scheduling operations. An attacker can remotely exploit this vulnerability without authentication or user interaction to execute arbitrary commands on the device. The vulnerability has a CVSS 4.0 base score of 5.3, indicating medium severity, with low complexity and no privileges required. Although no public exploits are currently known in the wild, the vulnerability has been publicly disclosed, increasing the risk of exploitation. Organizations using affected D-Link NAS devices should prioritize patching or apply mitigations to prevent remote command execution. This vulnerability poses risks to confidentiality, integrity, and availability of data stored on these devices.

Impact

The impact of CVE-2026-4196 is significant for organizations relying on affected D-Link NAS devices for critical data storage and backup. Successful exploitation allows remote attackers to execute arbitrary commands on the device, potentially leading to full compromise of the NAS system. This can result in unauthorized data access, data modification, deletion, or ransomware deployment. The compromise of backup systems can disrupt business continuity and data recovery processes. Since the vulnerability requires no authentication, attackers can scan for exposed devices and exploit them en masse, increasing the risk of widespread attacks. The medium CVSS score reflects moderate impact, but the ease of exploitation and the critical role of these devices in data infrastructure elevate the threat. Organizations with poor network segmentation or exposed management interfaces are particularly vulnerable. Additionally, attackers could use compromised NAS devices as footholds for lateral movement within corporate networks, escalating the overall security risk.

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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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