Cyber Resilience

CVE-2026-9477

HighRCE

Published: 25 May 2026

Published
25 May 2026
Modified
26 May 2026
KEV Added
—
Patch
—
CVSS Score v4 8.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/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 0.0191 77.2th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-9477 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 22.8% 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 security flaw has been discovered in Totolink A8000RU 7.1cu.643_b20200521. This issue affects the function setAccessDeviceCfg of the file /cgi-bin/cstecgi.cgi of the component Web Management Interface. Performing a manipulation of the argument mac results in os command injection. The attack is possible to be carried out remotely. The exploit has been released to the public and may be used for attacks.

The vulnerability permits unauthenticated remote attackers to inject and execute arbitrary operating system commands by supplying crafted mac parameters to the web management interface. Successful exploitation grants full control over the affected device, including the ability to read, modify, or delete data and disrupt device operation, consistent with the reported CVSS 8.9 rating and CWE-77/CWE-78 classifications.

Public references include a detailed proof-of-concept on GitHub along with entries in VulDB, but no vendor advisory or firmware patch information is provided in the available sources. The EPSS score has remained flat at 0.0125 with no material increase since disclosure.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability details

A security flaw has been discovered in Totolink A8000RU 7.1cu.643_b20200521. This issue affects the function setAccessDeviceCfg of the file /cgi-bin/cstecgi.cgi of the component Web Management Interface. Performing a manipulation of the argument mac results in os command injection. The attack…

more

is possible to be carried out remotely. The exploit has been released to the public and may be used for attacks.

CWE(s)
CWE-77CWE-78

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

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.
attack.mitre.org →
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
attack.mitre.org →
Why these techniques?

Remote OS command injection in web management interface directly enables T1190 (public app exploitation) and Unix shell command execution via T1059.004.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-7204Shared CWE-77, CWE-78
CVE-2026-2152Shared CWE-77, CWE-78
CVE-2026-5677Shared CWE-77, CWE-78
CVE-2026-2157Shared CWE-77, CWE-78
CVE-2026-7136Shared CWE-77, CWE-78
CVE-2026-7121Shared CWE-77, CWE-78
CVE-2026-9387Shared CWE-77, CWE-78
CVE-2026-2063Shared CWE-77, CWE-78
CVE-2026-2847Shared CWE-77, CWE-78
CVE-2026-9458Shared CWE-77, CWE-78

Affected Assets

Totolink
A8000RU
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match
prevent

Directly requires validation and sanitization of the untrusted 'mac' input parameter to the setAccessDeviceCfg function, blocking OS command injection.

AC-3 Access Enforcement good match
prevent

Enforces that the web management interface function cannot be invoked without proper authorization, preventing unauthenticated remote exploitation.

AC-17 Remote Access partial match
prevent

Restricts remote access to the device web interface, limiting exposure of the vulnerable cstecgi.cgi endpoint to only authorized management channels.

References