Cyber Resilience

CVE-2026-2120

RCE in Dlink Dir-823X Firmware 250416

Published
08 February 2026
Modified
11 February 2026
Patch / advisory
CVSS Score v4 7.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.039 89th percentile
Risk Priority 34 floored blend · peak EPSS

Summary

CVE-2026-2120 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 Command and Scripting Interpreter (T1059); ranked in the top 11% 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 map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-2120 is an OS command injection vulnerability (CWE-77, CWE-78) in the D-Link DIR-823X router running firmware version 250416. The issue affects an unknown function in the /goform/set_server_settings file within the Configuration Parameter Handler component. It is triggered by manipulating the terminal_addr, server_ip, or server_port arguments, allowing remote exploitation.

The vulnerability carries a CVSS v3.1 base score of 7.2 (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H). Remote attackers with high privileges, such as authenticated administrative users, can exploit it with low complexity and no user interaction. Successful exploitation enables arbitrary OS command execution, resulting in high impacts to confidentiality, integrity, and availability, potentially leading to full device compromise.

Advisories from VulDB, including entries at https://vuldb.com/?ctiid.344694, https://vuldb.com/?id.344694, and https://vuldb.com/?submit.746916, document the vulnerability. The D-Link website (https://www.dlink.com/) is referenced for potential firmware updates or further guidance. A public exploit is available via a GitHub issue at https://github.com/master-abc/cve/issues/26 and might be used in attacks.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A vulnerability was identified in D-Link DIR-823X 250416. This affects an unknown function of the file /goform/set_server_settings of the component Configuration Parameter Handler. The manipulation of the argument terminal_addr/server_ip/server_port leads to os command injection. The attack may be initiated remotely.…

more

The exploit is publicly available and might be used.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
T1059.008 Network Device CLI Execution
Adversaries may abuse scripting or built-in command line interpreters (CLI) on network devices to execute malicious command and payloads.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-1544Same product: Dlink Dir-823X
CVE-2026-2129Same product: Dlink Dir-823X
CVE-2026-2175Same product: Dlink Dir-823X
CVE-2026-2063Same product: Dlink Dir-823X
CVE-2026-2084Same product: Dlink Dir-823X
CVE-2026-2157Same product: Dlink Dir-823X
CVE-2026-2143Same product: Dlink Dir-823X
CVE-2026-2155Same product: Dlink Dir-823X
CVE-2026-2210Same product: Dlink Dir-823X
CVE-2026-2082Same product: Dlink Dir-823X

Affected Assets

dlink
dir-823x firmware
250416

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.2.3
  • V1.2.5
  • V1.2.8
  • V1.2.9

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover command-construction flaws before deployment.

Input validation directly stops construction of commands from untrusted data containing special elements.

Least privilege reduces the permissions available to any process that could be subverted by injected commands.

Least functionality restricts available OS commands and interpreters, limiting the blast radius of injection.

Secure engineering principles include proper neutralization and safe command construction practices.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input validation and neutralization that prevent command injection.

DE.CM-09 partial match
prevents

Runtime monitoring of software and data can detect anomalous command execution resulting from injection.

ID.RA-01 partial match
prevents

Identifying recorded vulnerabilities enables remediation of command-injection flaws before exploitation.

PR.PS-02 partial match
prevents

Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Secure coding standards require proper escaping and parameterization of commands, directly eliminating CWE-77.

finds

Security testing in development catches command-injection vulnerabilities before release.

prevents

Secure development life cycle mandates input validation and command construction practices that directly prevent command injection.

prevents

Application security requirements explicitly call for controls against injection flaws including command injection.

prevents

Secure architecture principles reduce the attack surface but do not prescribe the specific neutralization techniques needed.

none

Environment separation limits the blast radius of an exploited command injection but does not prevent the flaw itself.

References