# CVE-2026-9407: Totolink A8000RU command injection in setFirewallType

Source: https://junglewise.ai/threats/cve-2026-9407-totolink-a8000ru-command-injection-in-setfirewalltype  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-25. Updated: 2026-05-26  
License: CC BY 4.0 with a link back

CVE-2026-9407 · Severity: critical · CVSS 9.8 · Published 2026-05-25

A security vulnerability exists in the Totolink A8000RU wireless router, a device used to provide internet connectivity and network management. 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, unauthorized access to connected devices, or a total disruption of internet services.

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

## Quick answers

**Is CVE-2026-9407 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-9407 being exploited in the wild.

**How severe is CVE-2026-9407?** Critical severity, with a CVSS score of 9.8, published 25 May 2026.

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

**Is there a fix for CVE-2026-9407?** 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-2026-9407 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-9407?** 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) within the 'setFirewallType' function of the '/cgi-bin/cstecgi.cgi' component. The vulnerability is caused by improper neutralization of the 'firewallType' argument, which is passed from the web management interface to the 'Uci_Set_Str' function and eventually executed via 'execv()' in 'CsteSystem'. A remote, unauthenticated attacker can exploit this by sending a crafted POST request containing shell metacharacters (e.g., backticks) to execute arbitrary OS commands with elevated privileges. A public exploit (PoC) has been disclosed.

## Affected products

- Totolink A8000RU 7.1cu.643_b20200521

## Timeline

- 2026-05-25: disclosed: Vulnerability disclosed and CVE assigned

## References

- [https://github.com/Litengzheng/vuldb_new2/blob/main/A8000RU/vul_339/README.md](https://github.com/Litengzheng/vuldb_new2/blob/main/A8000RU/vul_339/README.md)
- [https://vuldb.com/submit/813442](https://vuldb.com/submit/813442)
- [https://vuldb.com/vuln/365388](https://vuldb.com/vuln/365388)
- [https://vuldb.com/vuln/365388/cti](https://vuldb.com/vuln/365388/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)