CVE-2026-2155
Published: 08 February 2026
Summary
CVE-2026-2155 is a high-severity Command Injection (CWE-77) vulnerability in Dlink Dir-823X Firmware. Its CVSS base score is 7.3 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 29.1% 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 AC-3 (Access Enforcement).
Deeper analysis
CVE-2026-2155 is an OS command injection vulnerability (CWE-77, CWE-78) affecting the D-Link DIR-823X router with firmware version 250416. The issue lies in the sub_4208A0 function of the /goform/set_dmz file within the Configuration Handler component, where manipulation of the dmz_host or dmz_enable arguments triggers command injection.
The vulnerability is remotely exploitable over the network (AV:N) with low complexity (AC:L), but requires high privileges (PR:H) and no user interaction (UI:N), maintaining unchanged scope (S:U). It carries a CVSS v3.1 base score of 7.2 (High), enabling attackers to achieve high impacts on confidentiality, integrity, and availability through arbitrary OS command execution.
Advisories and additional details are documented in references such as https://github.com/master-abc/cve/issues/32, https://vuldb.com/?ctiid.344857, https://vuldb.com/?id.344857, https://vuldb.com/?submit.748236, and https://vuldb.com/?submit.750038. An exploit for this vulnerability has been publicly released and may be used in attacks.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-5794
Vulnerability details
A security flaw has been discovered in D-Link DIR-823X 250416. The affected element is the function sub_4208A0 of the file /goform/set_dmz of the component Configuration Handler. The manipulation of the argument dmz_host/dmz_enable results in os command injection. The attack can…
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be executed remotely. The exploit has been released to the public and may be used for attacks.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
OS command injection in public-facing router web interface (/goform/set_dmz) directly enables remote exploitation of the device (T1190) and arbitrary Unix shell command execution (T1059.004).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires validation and sanitization of dmz_host/dmz_enable inputs to the /goform/set_dmz handler, blocking the OS command injection vector at its root.
Enforces access-control policy on the Configuration Handler so that only authorized subjects can invoke sub_4208A0, limiting who can reach the injectable parameters.
Restricts the high-privilege accounts that are permitted to access the DMZ configuration function, reducing the population that can exploit the flaw.