# CVE-2026-9386: Totolink A8000RU command injection in setLanguageCfg

Source: https://junglewise.ai/threats/cve-2026-9386-totolink-a8000ru-command-injection-in-setlanguagecfg  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-24. Updated: 2026-05-26  
License: CC BY 4.0 with a link back

CVE-2026-9386 · Severity: critical · CVSS 9.8 · Published 2026-05-24

A vulnerability exists in the Totolink A8000RU wireless router, a device used to provide internet connectivity and manage local networks. An attacker can exploit this flaw to take complete control of the router by executing unauthorized system commands. This could lead to the interception of network traffic, theft of sensitive data, or a total disruption of internet services for the home or office.

Technologies: [TOTOLINK A8000RU](https://junglewise.ai/threats/technologies/a8000ru). Vendors: [TOTOLINK](https://junglewise.ai/threats/vendors/totolink).

## Quick answers

**Is CVE-2026-9386 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-9386 being exploited in the wild.

**How severe is CVE-2026-9386?** Critical severity, with a CVSS score of 9.8, published 24 May 2026.

**Which products and versions are affected?** TOTOLINK A8000RU 7.1cu.643_b20200521.

**Is there a fix for CVE-2026-9386?** 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-2026-9386 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-9386?** Check whether you run TOTOLINK A8000RU 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 A8000RU router firmware version 7.1cu.643_b20200521. The flaw is located within the setLanguageCfg function in the /cgi-bin/cstecgi.cgi component of the Web Management Interface. The application fails to properly sanitize the 'lang' parameter before passing it to a system execution function (CsteSystem/execv). A remote, unauthenticated attacker can exploit this by sending a specially crafted HTTP POST request containing shell metacharacters in the 'lang' argument. Successful exploitation allows for arbitrary command execution with the privileges of the web server. A public exploit (PoC) is available.

## Affected products

- Totolink A8000RU 7.1cu.643_b20200521

## Timeline

- 2026-05-24: disclosed: Initial disclosure via VulDB and NVD
- 2026-05-24: advisory

## References

- [https://github.com/Litengzheng/vuldb_new2/blob/main/A8000RU/vul_333/README.md](https://github.com/Litengzheng/vuldb_new2/blob/main/A8000RU/vul_333/README.md)
- [https://vuldb.com/submit/813432](https://vuldb.com/submit/813432)
- [https://vuldb.com/vuln/365349](https://vuldb.com/vuln/365349)
- [https://vuldb.com/vuln/365349/cti](https://vuldb.com/vuln/365349/cti)
- [https://www.totolink.net/](https://www.totolink.net/)

## Related threats

- [Totolink A8000RU OS command injection in setParentalRules](https://junglewise.ai/threats/cve-2026-9478-totolink-a8000ru-os-command-injection-in-setparentalrules)
- [Totolink A8000RU command injection in setAccessDeviceCfg](https://junglewise.ai/threats/cve-2026-9477-totolink-a8000ru-command-injection-in-setaccessdevicecfg)
- [Totolink A8000RU command injection in setPasswordCfg](https://junglewise.ai/threats/cve-2026-9476-totolink-a8000ru-command-injection-in-setpasswordcfg)
- [Totolink A8000RU command injection in setIpQosRules](https://junglewise.ai/threats/cve-2026-9475-totolink-a8000ru-command-injection-in-setipqosrules)
- [Totolink A8000RU OS command injection in setWanCfg](https://junglewise.ai/threats/cve-2026-9458-totolink-a8000ru-os-command-injection-in-setwancfg)