CVE-2026-4206
Published: 16 March 2026
Summary
CVE-2026-4206 is a medium-severity Injection (CWE-74) vulnerability in Dlink Dnr-202L Firmware. Its CVSS base score is 5.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 13.3% of CVEs by exploit likelihood; 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).
Deeper analysis
CVE-2026-4206 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, in versions up to 20260205. The issue resides in the functions FMT_rebuild_diskmgr, FMT_create_diskmgr, and ScanDisk_run_e2fsck within the /cgi-bin/dsk_mgr.cgi script. It has been assigned CWE-74 and CWE-77, with 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), indicating medium severity.
The vulnerability enables remote command injection through manipulation of the affected CGI endpoints. Exploitation requires low privileges (PR:L), such as those of an authenticated user, with low attack complexity and no user interaction needed. Successful exploitation allows limited impacts on confidentiality, integrity, and availability, potentially enabling arbitrary command execution on the device.
References include GitHub repositories detailing the vulnerability (e.g., https://github.com/wudipjq/my_vuln/blob/main/D-Link8/vuln_138/138.md and vuln_139/139.md) and VulDB entries (https://vuldb.com/?ctiid.351118, https://vuldb.com/?id.351118, https://vuldb.com/?submit.770417). An exploit has been publicly disclosed, increasing the risk of active exploitation against unpatched devices. No specific patch or mitigation details are outlined in the available information.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-12282
Vulnerability details
A vulnerability was 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 affects the function FMT_rebuild_diskmgr/FMT_create_diskmgr/ScanDisk_run_e2fsck of the file /cgi-bin/dsk_mgr.cgi. Performing…
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a manipulation results in command injection. The attack is possible to be carried out remotely. The exploit has been made public and could be used.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability is a remote command injection in a public-facing CGI script on D-Link NAS devices, enabling exploitation of public-facing applications (T1190) and arbitrary Unix shell command execution (T1059.004).
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Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly prevents command injection by enforcing validation of user inputs to the vulnerable /cgi-bin/dsk_mgr.cgi endpoints.
Requires timely remediation of the command injection flaw in affected D-Link NAS firmware through patching or updates.
Enforces least privilege for low-privileged authenticated users (PR:L), limiting the scope and impact of injected commands.