CVE-2026-4206

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.