CVE-2026-1400 is a vulnerability classified under CWE-434 (Unrestricted Upload of File with Dangerous Type) found in the AI Engine – The Chatbot and AI Framework for WordPress plugin. The flaw exists in the rest_helpers_update_media_metadata function, which fails to properly validate file types during media metadata updates. Authenticated attackers with Editor-level access or higher can exploit this by first uploading a benign image file, then using the update_media_metadata REST API endpoint to rename the file extension to .php, effectively creating an executable PHP file within the WordPress uploads directory. This can lead to remote code execution (RCE) on the server hosting the WordPress site. The vulnerability affects all versions up to 3.3.2 inclusive. The CVSS 3.1 score of 7.2 indicates a high-severity issue with network attack vector, low attack complexity, requiring privileges but no user interaction, and impacting confidentiality, integrity, and availability. No patches are currently linked, and no known exploits have been reported in the wild, but the potential for exploitation is significant given the ability to execute arbitrary code remotely. This vulnerability is particularly dangerous because it leverages legitimate REST API endpoints and requires only Editor-level privileges, which are commonly granted to trusted users or compromised accounts. The lack of file type validation is a critical oversight in the plugin's media handling functionality.

For European organizations, this vulnerability poses a serious risk to WordPress-based websites using the AI Engine plugin. Successful exploitation can lead to remote code execution, allowing attackers to execute arbitrary commands, deploy malware, or pivot within the network. This threatens the confidentiality of sensitive data, integrity of website content, and availability of services. Organizations with multiple users having Editor or higher privileges are more vulnerable, as attackers can leverage compromised or malicious accounts. The impact extends to potential defacement, data breaches, and use of compromised servers for further attacks such as ransomware or lateral movement. Given WordPress's widespread use in Europe for corporate, governmental, and e-commerce sites, the vulnerability could disrupt critical services and damage reputations. The lack of known exploits currently suggests a window for proactive mitigation, but the ease of exploitation and high impact make this a pressing concern.

1. Immediately audit and restrict Editor-level and higher privileges to trusted users only, minimizing the attack surface. 2. Monitor file uploads and REST API usage for suspicious activity, especially attempts to rename files to executable extensions. 3. Implement web application firewall (WAF) rules to block unauthorized file uploads and suspicious REST API calls targeting update_media_metadata endpoints. 4. Disable or restrict the use of the vulnerable plugin until a security patch is released. 5. Regularly update WordPress core, plugins, and themes to the latest versions once patches addressing this vulnerability become available. 6. Employ file integrity monitoring on the uploads directory to detect unauthorized PHP files. 7. Use security plugins that enforce strict file type validation and scanning of uploaded files. 8. Educate users with elevated privileges about the risks and signs of compromise. 9. Consider isolating WordPress instances in segmented network zones to limit potential lateral movement. 10. Backup website data regularly and verify restoration procedures to mitigate impact of potential attacks.