CVE-2026-5849: Tenda i12 Path Traversal Vulnerability

CVE-2026-5849 Overview

A path traversal vulnerability has been identified in the Tenda i12 wireless access point running firmware version 1.0.0.11(3862). The vulnerability exists within an unspecified function of the HTTP Handler component, allowing remote attackers to manipulate input parameters to traverse directory paths and potentially access unauthorized files on the device. The exploit has been publicly disclosed, increasing the risk of active exploitation in the wild.

Critical Impact

Remote attackers can exploit this path traversal vulnerability to read sensitive files, configuration data, or credentials stored on the Tenda i12 device without authentication, potentially leading to full device compromise.

Affected Products

• Tenda i12 Firmware version 1.0.0.11(3862)

Discovery Timeline

• April 9, 2026 - CVE-2026-5849 published to NVD
• April 9, 2026 - Last updated in NVD database

Technical Details for CVE-2026-5849

Vulnerability Analysis

This vulnerability is classified as CWE-22 (Improper Limitation of a Pathname to a Restricted Directory), commonly known as path traversal or directory traversal. The flaw resides in the HTTP Handler component of the Tenda i12 firmware, where insufficient validation of user-supplied input allows attackers to escape the intended web root directory structure.

The network-accessible nature of this vulnerability means attackers can exploit it remotely without requiring any authentication or user interaction. When successfully exploited, the vulnerability can lead to unauthorized read access to sensitive system files, configuration files containing credentials, or other protected data stored on the device's file system.

Root Cause

The root cause of CVE-2026-5849 is improper input validation within the HTTP Handler component. The affected function fails to adequately sanitize user-supplied file path parameters, allowing malicious sequences such as ../ to traverse outside the intended directory boundaries. This lack of proper path canonicalization enables attackers to access files and directories that should be restricted.

Attack Vector

The attack vector for this vulnerability is network-based, requiring no authentication or special privileges. An attacker can craft malicious HTTP requests containing directory traversal sequences targeting the vulnerable HTTP Handler component. These sequences allow the attacker to navigate the file system hierarchy and access sensitive files outside the web root.

Typical exploitation involves sending HTTP requests with path traversal payloads such as ../../etc/passwd or similar sequences designed to read system configuration files, credential stores, or other sensitive data. The publicly disclosed nature of this exploit means that proof-of-concept techniques may already be available to threat actors.

Detection Methods for CVE-2026-5849

Indicators of Compromise

• HTTP requests containing repeated ../ or ..%2f sequences targeting the Tenda i12 device
• Access log entries showing attempts to read files outside the web root directory
• Requests for sensitive system files such as /etc/passwd, /etc/shadow, or configuration files
• Unusual file access patterns or data exfiltration from the device

Detection Strategies

• Monitor HTTP access logs for requests containing path traversal patterns including encoded variants (%2e%2e%2f, ..%252f)
• Deploy web application firewall (WAF) rules to detect and block directory traversal attempts
• Implement intrusion detection system (IDS) signatures for path traversal attack patterns targeting Tenda devices
• Review network traffic for anomalous HTTP requests to the device's management interface

Monitoring Recommendations

• Enable verbose logging on the Tenda i12 device if available and forward logs to a centralized SIEM
• Monitor for repeated failed or suspicious HTTP requests from external IP addresses
• Set up alerts for access to sensitive file paths commonly targeted in path traversal attacks
• Regularly audit device access logs for unauthorized file access attempts

How to Mitigate CVE-2026-5849

Immediate Actions Required

• Restrict network access to the Tenda i12 management interface to trusted IP addresses only
• Place the device behind a properly configured firewall with strict access control rules
• Disable remote management access if not required for operations
• Monitor the Tenda Official Website for firmware updates addressing this vulnerability

Patch Information

As of the publication date, no vendor patch has been officially announced for this vulnerability. Organizations should monitor Tenda's official security advisories and apply firmware updates as soon as they become available. Additional technical details can be found in the VulDB Vulnerability Details and the GitHub Repository Documentation.

Workarounds

• Implement network segmentation to isolate the Tenda i12 device from untrusted networks
• Use a reverse proxy with input validation to filter malicious requests before they reach the device
• Restrict access to the HTTP management interface using firewall rules or access control lists (ACLs)
• Consider deploying an alternative device if a timely patch is not made available by the vendor

# Example firewall rule to restrict access to Tenda i12 management interface
# Replace 192.168.1.100 with your Tenda device IP and 10.0.0.0/24 with trusted management network
iptables -A INPUT -d 192.168.1.100 -p tcp --dport 80 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -d 192.168.1.100 -p tcp --dport 80 -j DROP