CVE-2026-9408
Published: 25 May 2026
Summary
CVE-2026-9408 is a high-severity Command Injection (CWE-77) vulnerability in Totolink A8000RU (inferred from references). Its CVSS base score is 8.9 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 25.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 AC-3 (Access Enforcement) and SI-10 (Information Input Validation).
Deeper analysis
A vulnerability was detected in the Totolink A8000RU router running firmware version 7.1cu.643_b20200521. The issue resides in the setStaticDhcpRules function within the /cgi-bin/cstecgi.cgi file of the Web Management Interface, where improper handling of the enable argument permits OS command injection. The flaw is tracked under CWE-77 and CWE-78 and carries a CVSS 4.0 score of 8.9, reflecting network-accessible attack vectors that require no authentication or user interaction.
An unauthenticated remote attacker can supply crafted input to the affected parameter and execute arbitrary operating system commands on the device. Successful exploitation grants full control over the router, enabling actions such as configuration changes, traffic interception, or persistence mechanisms. The exploit code has been made publicly available.
The EPSS score remains flat at 0.0125 with no material increase since disclosure. Public references include a detailed proof-of-concept on GitHub along with entries on Vuldb, but no vendor advisory or patch information is provided in the available sources.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-31609
Vulnerability details
A vulnerability was detected in Totolink A8000RU 7.1cu.643_b20200521. Affected by this issue is the function setStaticDhcpRules of the file /cgi-bin/cstecgi.cgi of the component Web Management Interface. The manipulation of the argument enable results in os command injection. The attack may…
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be performed from remote. The exploit is now public and may be used.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Remote OS command injection in web management interface directly enables T1190 (exploit public-facing app) for initial access and T1059.004 (Unix shell) for arbitrary command execution.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly enforces authentication and authorization checks on the /cgi-bin/cstecgi.cgi web interface before allowing any manipulation of the enable argument in setStaticDhcpRules.
Requires validation and sanitization of the enable parameter to block the crafted input that produces OS command injection under CWE-77/78.
Mandates identification and authentication of all users before granting access to the unauthenticated remote management function that is currently exposed.