CVE-2026-0829 is a security vulnerability classified under CWE-862 (Missing Authorization) affecting the Frontend File Manager WordPress plugin through version 23.5. The flaw arises because the plugin fails to enforce proper authorization checks on critical functionalities. Specifically, unauthenticated users can exploit the plugin to send emails through the WordPress site without any validation, effectively using the site as an open mail relay. This can facilitate large-scale spam or phishing campaigns originating from legitimate domains, undermining email trust and potentially causing blacklisting of the domain. Furthermore, the vulnerability allows attackers to guess file IDs to access uploaded files arbitrarily, bypassing intended access controls and exposing sensitive or confidential data. The lack of authentication requirements and user interaction makes exploitation straightforward. Although no public exploits have been reported yet, the vulnerability's nature and impact make it a significant threat. The plugin is widely used in WordPress environments, which are prevalent across many European organizations, especially in small to medium enterprises and content-driven websites. The absence of a CVSS score necessitates an independent severity assessment, which rates this vulnerability as high due to its potential impact on confidentiality, integrity, and availability, combined with ease of exploitation and broad attack surface. No official patches or mitigations are currently linked, emphasizing the need for immediate defensive measures.

For European organizations, this vulnerability can lead to multiple severe consequences. The ability to send unauthenticated emails through legitimate WordPress sites can result in the organization’s domain being used for spam or phishing, damaging brand reputation and causing email blacklisting by providers, which disrupts legitimate communications. The unauthorized access to uploaded files risks exposure of sensitive business data, personal information, or intellectual property, potentially violating GDPR and other data protection regulations, leading to legal and financial penalties. The exploitation could also be leveraged as a foothold for further attacks or lateral movement within the network. Given the widespread use of WordPress in Europe, especially among SMEs and public sector websites, the threat surface is substantial. The reputational damage and operational disruptions could be significant, particularly for organizations relying heavily on their online presence and email communications. Additionally, the lack of authentication requirements means that attackers can exploit this vulnerability remotely and anonymously, increasing the risk of widespread abuse.

Organizations should immediately audit their WordPress installations to identify if the Frontend File Manager plugin is in use and confirm the version. Until an official patch is released, it is advisable to disable or uninstall the plugin to eliminate the attack vector. If disabling is not feasible, restrict access to the plugin’s functionality by implementing web application firewall (WAF) rules that block unauthenticated requests to the plugin endpoints, especially those related to email sending and file access. Monitor outgoing email traffic for unusual patterns indicative of spam or relay abuse and configure rate limiting where possible. Review and tighten file permissions and access controls on uploaded files to prevent unauthorized enumeration or access. Regularly update WordPress core and plugins to the latest versions once patches become available. Additionally, implement logging and alerting for suspicious activities related to the plugin. Educate site administrators about the risks and encourage prompt action to mitigate exposure.