CVE-2026-8263 Overview
CVE-2026-8263 is an operating system command injection vulnerability affecting Tenda AC10U firmware version 15.03.06.49_multi_TDE01. The flaw resides in the fromSetWirelessRepeat function inside /goform/WifiExtraSet, which is handled by the device httpd component. Attackers can manipulate the mac or ssid arguments to inject arbitrary operating system commands. The vulnerability is reachable over the network, and a public proof-of-concept has been released. The issue is tracked under [CWE-77] (Improper Neutralization of Special Elements used in a Command) and [CWE-787] (Out-of-bounds Write).
Critical Impact
Authenticated remote attackers can inject operating system commands through the wireless repeater configuration handler on Tenda AC10U routers, with a public exploit available.
Affected Products
- Tenda AC10U firmware 15.03.06.49_multi_TDE01
- Tenda AC10U hardware revision 1.0
- Tenda httpd component exposing /goform/WifiExtraSet
Discovery Timeline
- 2026-05-11 - CVE-2026-8263 published to NVD
- 2026-05-12 - Last updated in NVD database
Technical Details for CVE-2026-8263
Vulnerability Analysis
The vulnerability exists in the fromSetWirelessRepeat handler within the embedded httpd web server on the Tenda AC10U router. The handler processes HTTP requests targeting /goform/WifiExtraSet, which is used to configure wireless repeater settings. The mac and ssid parameters submitted in the request body are passed into a system command construction routine without proper sanitization. An attacker who can authenticate to the device web interface can supply shell metacharacters in these fields to break out of the intended command context. Successful exploitation results in arbitrary command execution under the privileges of the httpd process, which typically runs as root on Tenda consumer devices. The associated [CWE-787] entry indicates that the same input path also reaches an out-of-bounds write condition, which can corrupt memory beyond the command injection impact.
Root Cause
The root cause is the absence of input validation and command argument escaping in the fromSetWirelessRepeat function. User-controlled values for mac and ssid are concatenated directly into shell commands invoked through system call primitives. Tenda's web stack treats these fields as trusted configuration data rather than untrusted network input.
Attack Vector
The attack vector is network-based against the router HTTP management interface. An attacker authenticated to the device sends a crafted POST request to /goform/WifiExtraSet with malicious shell syntax in the mac or ssid parameters. No user interaction is required beyond the initial authenticated session. Detailed reproduction steps are documented in the GitHub PoC Documentation and the VulDB Vulnerability #362560 entry.
// No verified exploit code is reproduced here.
// See the referenced PoC documentation for technical details.
Detection Methods for CVE-2026-8263
Indicators of Compromise
- HTTP POST requests to /goform/WifiExtraSet containing shell metacharacters such as ;, |, `, or $() within the mac or ssid parameters.
- Unexpected outbound connections originating from the router management plane following configuration changes.
- Modifications to router startup scripts, /etc/, or /tmp/ paths that were not initiated by an administrator.
Detection Strategies
- Inspect router web traffic for malformed mac parameters that do not match the XX:XX:XX:XX:XX:XX MAC address format.
- Alert on ssid values containing non-printable characters or command separators in HTTP request bodies.
- Correlate authenticated admin sessions with subsequent anomalous DNS queries or outbound TCP connections from the router.
Monitoring Recommendations
- Log all administrative HTTP requests reaching the router and forward them to a central collection point for review.
- Monitor router firmware integrity and configuration backups for unexplained changes.
- Track failed and successful logins to the Tenda management interface to identify brute-force or credential reuse attempts that precede exploitation.
How to Mitigate CVE-2026-8263
Immediate Actions Required
- Restrict access to the router web management interface to trusted internal hosts and disable remote (WAN-side) administration.
- Rotate the administrative password for the AC10U device and audit any accounts with web management privileges.
- Review router logs and configuration for signs of unauthorized command execution or persistence.
Patch Information
At the time of publication, no vendor advisory or fixed firmware version has been associated with CVE-2026-8263 in the NVD record. Check the Tenda Official Website for updated firmware releases for the AC10U platform, and apply any subsequent security update that addresses the fromSetWirelessRepeat handler.
Workarounds
- Disable the wireless repeater feature when it is not required for the deployment.
- Place the router management interface behind a network segment that is not reachable from untrusted Wi-Fi clients or guest networks.
- Replace end-of-support Tenda AC10U units with a supported model if no firmware fix becomes available.
# Example: block external access to the router admin interface using iptables on an upstream gateway
iptables -A FORWARD -p tcp -d <router_ip> --dport 80 -s <trusted_admin_subnet> -j ACCEPT
iptables -A FORWARD -p tcp -d <router_ip> --dport 80 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
