CVE-2026-4214
Published: 16 March 2026
Summary
CVE-2026-4214 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Dlink Dnr-202L Firmware. Its CVSS base score is 7.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 48.5% 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-16 (Memory Protection).
Deeper analysis
CVE-2026-4214 is a stack-based buffer overflow vulnerability affecting the UPnP_AV_Server_Path_Setting function in the /cgi-bin/app_mgr.cgi file across multiple D-Link NAS devices, including 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 up to version 20260205. The flaw, associated with CWEs-119, CWE-121, and CWE-787, was published on 2026-03-16.
The vulnerability carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating it can be exploited remotely over the network with low complexity by an attacker possessing low privileges. Successful exploitation triggers a stack-based buffer overflow, potentially enabling high-impact compromise of confidentiality, integrity, and availability, such as arbitrary code execution.
Advisories and further details, including potential mitigations or patches, are documented on VulDB (https://vuldb.com/?ctiid.351125, https://vuldb.com/?id.351125, https://vuldb.com/?submit.770445) and the D-Link website (https://www.dlink.com/). A public exploit is available on GitHub (https://github.com/wudipjq/my_vuln/blob/main/D-Link8/vuln_164/164.md), increasing the risk of real-world attacks on unpatched devices.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-12329
Vulnerability details
A flaw 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 issue affects the function UPnP_AV_Server_Path_Setting of the file…
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/cgi-bin/app_mgr.cgi. Executing a manipulation can lead to stack-based buffer overflow. The attack may be launched remotely. The exploit has been published and may be used.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Remote stack buffer overflow in public-facing web CGI (/cgi-bin/app_mgr.cgi) on NAS devices allows authenticated low-priv remote attackers to achieve arbitrary code execution, directly mapping to exploitation of public-facing apps (T1190) and exploitation for privilege escalation (T1068).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly mitigates the stack-based buffer overflow by identifying, reporting, and applying firmware patches for the vulnerable UPnP_AV_Server_Path_Setting function in affected D-Link NAS devices.
Requires validation of inputs to the /cgi-bin/app_mgr.cgi UPnP path setting function to prevent stack buffer overflows from malformed data.
Implements memory safeguards such as stack canaries, DEP, and ASLR to block arbitrary code execution from stack-based buffer overflow exploits.