Cyber Posture

CVE-2026-4196

MediumPublic PoC

Published: 16 March 2026

Published
16 March 2026
Modified
19 March 2026
KEV Added
Patch
CVSS Score 6.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
EPSS Score 0.0014 33.9th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-4196 is a medium-severity Injection (CWE-74) vulnerability in Dlink Dns-1550-04 Firmware. Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 33.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Requires timely remediation of the specific command injection flaw in vulnerable D-Link NAS firmware versions up to 20260205.

prevent

Enforces validation and sanitization of inputs to cgi_recovery, cgi_backup_now, cgi_set_schedule, and cgi_set_rsync_server functions to prevent command injection.

prevent

Limits privileges of the CGI script processes to minimize impact of injected commands even if exploitation occurs with low-privilege access.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
Why these techniques?

CVE enables exploitation of public-facing web application (NAS CGI script) for remote command injection, facilitating Unix Shell execution.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

NVD Description

A vulnerability has been found in D-Link DNS-120, DNR-202L, DNS-315L, DNS-320, DNS-320L, DNS-320LW, DNS-321, DNR-322L, DNS-323, DNS-325, DNS-326, DNS-327L, DNR-326, DNS-340L, DNS-343, DNS-345, DNS-726-4, DNS-1100-4, DNS-1200-05 and DNS-1550-04 up to 20260205. This impacts the function cgi_recovery/cgi_backup_now/cgi_set_schedule/cgi_set_rsync_server of the file /cgi-bin/remote_backup.cgi.…

more

The manipulation leads to command injection. The attack is possible to be carried out remotely. The exploit has been disclosed to the public and may be used.

Deeper analysisAI

CVE-2026-4196 is a command injection vulnerability affecting multiple D-Link network-attached storage (NAS) devices, including models DNS-120, DNR-202L, DNS-315L, DNS-320, DNS-320L, DNS-320LW, DNS-321, DNR-322L, DNS-323, DNS-325, DNS-326, DNS-327L, DNR-326, DNS-340L, DNS-343, DNS-345, DNS-726-4, DNS-1100-4, DNS-1200-05, and DNS-1550-04 running firmware versions up to 20260205. The issue resides in the cgi_recovery, cgi_backup_now, cgi_set_schedule, and cgi_set_rsync_server functions within the /cgi-bin/remote_backup.cgi script. It has a CVSS v3.1 base score of 6.3 (AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L) and is associated with CWE-74 (Improper Neutralization of Special Elements) and CWE-77 (Command Injection).

The vulnerability can be exploited remotely by an attacker with low privileges (PR:L), requiring network access and low attack complexity but no user interaction. Successful exploitation allows command injection, enabling limited impacts on confidentiality, integrity, and availability, such as potential execution of arbitrary commands within the context of the affected CGI script.

Advisories and additional details are available via VulDB (ctiid.351108, id.351108, submit.769855) and GitHub repositories documenting the vulnerability (wudipjq/my_vuln D-Link8/vuln_98/98.md and vuln_99/99.md). The exploit has been publicly disclosed and may be in use.

In context, the vulnerability was published on 2026-03-16, with public exploit availability increasing the risk for unpatched D-Link NAS deployments.

Details

CWE(s)

Affected Products

dlink
dns-1550-04 firmware
≤ 2026-02-05
dlink
dns-315l firmware
≤ 2026-02-05
dlink
dns-320 firmware
≤ 2026-02-05
dlink
dns-320l firmware
≤ 2026-02-05
dlink
dns-320lw firmware
≤ 2026-02-05
dlink
dns-321 firmware
≤ 2026-02-05
dlink
dns-322l firmware
≤ 2026-02-05
dlink
dns-323 firmware
≤ 2026-02-05
dlink
dns-325 firmware
≤ 2026-02-05
dlink
dns-326 firmware
≤ 2026-02-05
+10 more product configuration(s) — see NVD for full list

CVEs Like This One

CVE-2026-4203Same product: Dlink Dnr-202L
CVE-2026-4207Same product: Dlink Dnr-202L
CVE-2026-4195Same product: Dlink Dnr-202L
CVE-2026-4209Same product: Dlink Dnr-202L
CVE-2026-4210Same product: Dlink Dnr-202L
CVE-2026-4204Same product: Dlink Dnr-202L
CVE-2026-4197Same product: Dlink Dnr-202L
CVE-2026-4205Same product: Dlink Dnr-202L
CVE-2026-4206Same product: Dlink Dnr-202L
CVE-2026-4211Same product: Dlink Dnr-202L

References