CVE-2026-9433: Totolink A8000RU command injection in setMacFilterRules

CVE-2026-9433 · Severity: critical · CVSS 9.8 · Published 2026-05-25

The Totolink A8000RU router, a device used to provide wireless internet connectivity, contains a critical security flaw in its web management interface. An attacker can exploit this vulnerability to take complete control of the router by sending a specially crafted network request. This could lead to the interception of internet traffic, unauthorized access to the local network, or a total disruption of internet service.

Technologies: TOTOLINK A8000RU. Vendors: TOTOLINK.

Quick answers

Is CVE-2026-9433 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-9433 being exploited in the wild.
How severe is CVE-2026-9433?
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-2026-9433?
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-2026-9433 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-9433?
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 'setMacFilterRules' function of the /cgi-bin/cstecgi.cgi component. The vulnerability is rooted in the improper sanitization of the 'enable' parameter, which is passed to the 'Uci_Set_Str' function and eventually executed via 'execv()' through the 'CsteSystem' function. A remote, unauthenticated attacker can exploit this by sending a crafted POST request containing shell metacharacters (e.g., backticks) in the 'enable' field. Successful exploitation allows for arbitrary command execution with the privileges of the web server, potentially leading to full system compromise. A public exploit (PoC) is available.

Affected products

  • Totolink A8000RU 7.1cu.643_b20200521

Timeline

  • 2026-05-25: disclosed: Vulnerability details and PoC published via GitHub and VulDB.
  • 2026-05-25: advisory: CVE-2026-9433 published.

References

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