CVE-2026-5213: Stack Buffer Overflow in D-Link DNS <=20260205

CVE-2026-5213 affects several D-Link DNS devices, including models like DNS-120, DNR-202L, and others listed, up to the date 20260205. It's a stack-based buffer overflow vulnerability located in the cgiaddusertosession function of the /cgi-bin/accountmgr.cgi file. This flaw allows a remote attacker to manipulate the read_list argument, potentially leading to arbitrary code execution on the device. The vulnerability's severity is rated as CVSS 8.8, indicating a high risk. Successful exploitation could compromise the confidentiality, integrity, and availability of the device, enabling unauthorized access to sensitive data and control of the device itself.

1. Reserved2026-03-31
2. Published2026-03-31
3. Modified2026-04-01
4. EPSS updated2026-04-08

Currently, no official fix has been released by D-Link for this vulnerability. The most effective mitigation is to discontinue use of the affected devices until a firmware update is available. As a temporary measure, segmenting affected devices on an isolated network can help limit the potential impact of an exploitation. Actively monitoring device logs for suspicious activity can also aid in detecting and responding to potential attacks. It is advised to contact D-Link for information regarding future security updates.