CVE-2026-5688: Totolink A7100RU cstecgi.cgi setDdnsCfg os command injection

Vulnerability summary

CVE-2026-5688 is a high (CVSS 7.5) Command Injection vulnerability in totolink a7100ru_firmware. EPSS estimates a 2.06% chance of exploitation in the next 30 days, higher than 81.1% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 06-04-2026
   PublishedVulnerability first disclosed.
2. 08-04-2026
   Last modifiedVulnerability information updated.

Description

A security vulnerability has been detected in Totolink A7100RU 7.4cu.2313_b20191024. Impacted is the function setDdnsCfg of the file /cgi-bin/cstecgi.cgi. Such manipulation of the argument provider leads to os command injection. The attack may be launched remotely. The exploit has been disclosed publicly and may be used.

• CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.
• CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.