Cyber Posture

CVE-2026-7139

Critical

Published: 27 April 2026

Published
27 April 2026
Modified
27 April 2026
KEV Added
Patch
CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0125 79.5th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Description

Adversaries may abuse Unix shell commands and scripts for execution.

Security Summary

CVE-2026-7139 is an OS command injection vulnerability (CWE-77, CWE-78) affecting the Totolink A8000RU router on firmware version 7.1cu.643_b20200521. The issue lies in the setWiFiAclRules function of the /cgi-bin/cstecgi.cgi CGI handler component, where manipulation of the "mode" argument triggers command injection.

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), making it remotely exploitable over the network by unauthenticated attackers with low attack complexity and no user interaction. Exploitation enables arbitrary OS command execution, granting high-impact access to confidentiality, integrity, and availability of the affected device.

Advisories referenced in VulDB (vuln/359738 and related CTI) and a GitHub repository detail the vulnerability, with the exploit publicly available and usable. The vendor's site at totolink.net is listed, though no specific patches or mitigations are outlined in the provided references.

The published exploit elevates the risk of real-world exploitation against unpatched Totolink A8000RU devices.

Details

CWE(s)
CWE-77CWE-78

MITRE ATT&CK Enterprise Techniques

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

The vulnerability is an unauthenticated remote OS command injection in a public-facing router web CGI interface (T1190: Exploit Public-Facing Application), directly enabling arbitrary Unix shell command execution (T1059.004) on the device.

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

References