CVE-2026-78063 Overview
CVE-2026-78063 is a command injection vulnerability affecting Tenda CH22 firmware version 1.0.0.1. The flaw resides in the formeditFileName function accessible through the /goform/editFileName endpoint. Attackers can manipulate the editNameMit argument to inject arbitrary operating system commands. The issue is classified under [CWE-74] (Improper Neutralization of Special Elements in Output Used by a Downstream Component). The attack can be launched remotely, and public exploit details have been released.
Critical Impact
Remote attackers with low-level authentication can inject operating system commands on affected Tenda CH22 devices, potentially leading to unauthorized configuration changes or further network compromise.
Affected Products
- Tenda CH22 firmware version 1.0.0.1
- /goform/editFileName web interface endpoint
- formeditFileName handler function
Discovery Timeline
- 2026-08-23 - CVE-2026-78063 published to NVD
- 2026-08-24 - Last updated in NVD database
Technical Details for CVE-2026-78063
Vulnerability Analysis
The vulnerability affects the web management interface of the Tenda CH22 router. When a request is submitted to /goform/editFileName, the formeditFileName handler processes the editNameMit parameter without adequate neutralization of shell metacharacters. Because the parameter is passed to a downstream operating system command, an attacker can append or chain additional commands to the intended input. The Exploit Prediction Scoring System (EPSS) probability is approximately 1.07%, placing the vulnerability in the 62nd percentile for likelihood of exploitation.
Root Cause
The underlying weakness is improper neutralization of special elements passed to a downstream OS command interpreter. The formeditFileName function accepts user-controllable input via the editNameMit argument and forwards it to a system call without input sanitization, argument escaping, or use of a safe execution API. This is a classic pattern documented in [CWE-74] injection weaknesses.
Attack Vector
Exploitation occurs over the network against the router's HTTP management interface. An authenticated user with low privileges submits a crafted POST request to /goform/editFileName containing shell metacharacters in the editNameMit field. The injected commands execute in the context of the router's web service. Public references, including a VulDB entry and a technical write-up hosted on Notion, describe the exploitation path. See the Notion write-up on Tenda CH22 formeditFileName and the VulDB CVE-2026-78063 Entry for additional context.
No verified proof-of-concept code is included here. Refer to the linked references for technical exploitation details.
Detection Methods for CVE-2026-78063
Indicators of Compromise
- HTTP POST requests to /goform/editFileName containing shell metacharacters such as ;, |, &, backticks, or $() in the editNameMit parameter.
- Unexpected child processes spawned by the router's HTTP daemon (httpd or vendor-equivalent binary).
- Outbound network connections from the router to unknown external hosts following administrative requests.
Detection Strategies
- Inspect web-server logs on Tenda CH22 devices for requests to /goform/editFileName with non-alphanumeric payloads in editNameMit.
- Deploy network-level signatures on IDS/IPS platforms to flag command-injection patterns targeting /goform/ endpoints.
- Correlate administrative session activity with subsequent anomalous device behavior such as new listening ports or DNS queries.
Monitoring Recommendations
- Forward router syslog and HTTP access logs to a centralized logging platform for retention and search.
- Baseline normal administrative traffic to the router and alert on deviations targeting goform handlers.
- Monitor egress traffic from network infrastructure devices, which should rarely initiate outbound connections.
How to Mitigate CVE-2026-78063
Immediate Actions Required
- Restrict access to the router's web management interface to trusted management VLANs or specific administrative hosts.
- Disable remote WAN-side management on Tenda CH22 devices if it is enabled.
- Rotate administrative credentials to reduce the impact of authenticated exploitation.
- Audit device configurations and logs for signs of prior exploitation.
Patch Information
At the time of publication, no vendor patch has been referenced in the NVD entry for CVE-2026-78063. Monitor the Tenda Official Website for firmware updates addressing the formeditFileName command injection. Apply firmware updates immediately once released.
Workarounds
- Segment router management interfaces onto isolated networks accessible only through jump hosts.
- Enforce access control lists restricting HTTP/HTTPS management traffic to authorized IP addresses.
- Replace end-of-life or unpatched devices with supported hardware if a vendor fix is not made available.
# Example ACL restricting management access to a trusted subnet
iptables -A INPUT -p tcp --dport 80 -s 192.0.2.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -s 192.0.2.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
