Quick answers
- Is CVE-2026-5688 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-5688 being exploited in the wild.
- How severe is CVE-2026-5688?
- High severity, with a CVSS score of 7.3, published 6 April 2026.
- Which products and versions are affected?
- TOTOLINK A7100ru 7.4cu.2313_b20191024.
- Is there a fix for CVE-2026-5688?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-5688 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-5688?
- Check whether you run TOTOLINK A7100ru at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
An OS command injection vulnerability exists in the Totolink A7100RU router firmware version 7.4cu.2313_b20191024. The flaw is located within the 'setDdnsCfg' function of the '/cgi-bin/cstecgi.cgi' binary. The application fails to properly sanitize the 'provider' parameter before passing it to the 'CsteSystem' function, which eventually executes the input via 'execv()'. A remote, unauthenticated attacker can exploit this by sending a crafted POST request containing shell metacharacters (e.g., backticks) in the JSON payload. Successful exploitation allows for arbitrary command execution with the privileges of the web server. A public PoC demonstrating the use of 'wget' for command execution has been disclosed.
Affected products
- Totolink A7100RU 7.4cu.2313_b20191024
Timeline
- 2026-04-06: disclosed: Initial public disclosure via VulDB and GitHub PoC
- 2026-04-06: advisory: CVE-2026-5688 published