CVE-2026-5854
Published: 09 April 2026
Summary
CVE-2026-5854 is a high-severity Command Injection (CWE-77) vulnerability in Totolink A7100RU (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 3.3% 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 RA-5 (Vulnerability Monitoring and Scanning) and SI-10 (Information Input Validation).
Deeper analysis
CVE-2026-5854 is an OS command injection vulnerability (CWE-77, CWE-78) in the Totolink A7100RU router running firmware version 7.4cu.2313_b20191024. The issue affects the setWiFiEasyCfg function within the /cgi-bin/cstecgi.cgi file of the CGI Handler component, where manipulation of the "merge" argument enables arbitrary command execution.
The vulnerability carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating it is exploitable remotely over the network with low complexity, no privileges, and no user interaction required. Attackers can send crafted requests to the affected endpoint, achieving high-impact confidentiality, integrity, and availability compromises, such as full router compromise.
Advisories and details are documented on VulDB (vuln/356380 and related pages), with a public exploit available in a GitHub repository at Litengzheng/vuldb_new/blob/main/A7100RU/vul_160/README.md. Security practitioners should check the vendor site at totolink.net for any firmware updates or mitigation guidance.
The exploit is public and may be used, increasing the risk of active exploitation against unpatched Totolink A7100RU devices.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-20870
Vulnerability details
A vulnerability was detected in Totolink A7100RU 7.4cu.2313_b20191024. Affected by this issue is the function setWiFiEasyCfg of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. Performing a manipulation of the argument merge results in os command injection. It is possible…
more
to initiate the attack remotely. The exploit is now public and may be used.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
CVE enables unauthenticated remote exploitation of a public-facing web application (T1190) leading to OS command injection on a likely Linux-based router (T1059.004).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly mitigates CVE-2026-5854 by requiring timely identification, reporting, and correction of the OS command injection flaw in the Totolink router firmware.
Prevents exploitation of the vulnerability by implementing input validation mechanisms on the 'merge' argument in the setWiFiEasyCfg CGI function to block command injection.
Enables proactive discovery and remediation of the command injection vulnerability through regular vulnerability scanning of the affected router firmware.