CVE-2025-53453 is a Remote File Inclusion (RFI) vulnerability found in the axiomthemes Hygia WordPress theme, specifically affecting versions up to 1.16. The vulnerability arises from improper control over the filename parameter used in PHP include or require statements, allowing an attacker to specify a remote URL to be included and executed by the server. This flaw enables unauthenticated remote attackers to execute arbitrary PHP code on the target server by supplying a crafted URL parameter, leading to potential full compromise of the web application environment. The vulnerability does not require any user interaction or prior authentication, making it highly exploitable over the network. The CVSS v3.1 score of 8.2 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N) indicates that the attack vector is network-based, with low attack complexity, no privileges or user interaction needed, and results in high confidentiality impact and partial integrity impact, but no availability impact. While no public exploits are currently known, the nature of RFI vulnerabilities historically makes them attractive targets for attackers to deploy web shells, steal sensitive data, or pivot within compromised networks. The vulnerability affects the PHP codebase of the Hygia theme, which is used by WordPress sites to manage website appearance and functionality. Since WordPress is widely used across Europe, especially in small and medium enterprises, this vulnerability poses a significant risk to organizations running unpatched versions of the theme. The lack of available patches at the time of disclosure necessitates immediate mitigation steps to prevent exploitation. The vulnerability was reserved in June 2025 and published in December 2025, indicating a recent discovery and disclosure timeline.

European organizations using the axiomthemes Hygia WordPress theme on their public-facing websites face significant risks from this vulnerability. Successful exploitation can lead to unauthorized remote code execution, allowing attackers to gain access to sensitive data, modify website content, or deploy persistent backdoors. This compromises the confidentiality and integrity of organizational data and can lead to reputational damage, regulatory non-compliance (e.g., GDPR violations), and potential financial losses. Since many European SMEs rely on WordPress themes like Hygia for their online presence, the attack surface is broad. The vulnerability’s network-exploitable nature means attackers can target these organizations remotely without needing credentials or user interaction. Additionally, compromised websites can be used as launchpads for further attacks within corporate networks or to distribute malware to visitors. The lack of availability impact suggests that denial-of-service is unlikely, but the confidentiality breach alone is critical. Organizations in sectors such as finance, healthcare, and government, which handle sensitive personal or financial data, are particularly at risk. The timing of the vulnerability disclosure also means organizations must act swiftly to avoid exploitation by opportunistic threat actors.

1. Immediately monitor for updates or patches from axiomthemes and apply them as soon as they become available to remediate the vulnerability. 2. Until patches are released, disable the PHP allow_url_include directive in the server’s php.ini configuration to prevent remote file inclusion. 3. Implement strict input validation and sanitization on all parameters that influence include or require statements to ensure only trusted local files can be referenced. 4. Employ Web Application Firewalls (WAFs) with rules designed to detect and block attempts to exploit RFI vulnerabilities, such as suspicious URL parameters containing remote URLs. 5. Conduct thorough code reviews of the theme and any custom plugins to identify and remediate unsafe dynamic includes. 6. Restrict file permissions and isolate the web server environment using containerization or sandboxing to limit the impact of potential code execution. 7. Regularly audit web server logs for unusual requests that may indicate exploitation attempts. 8. Educate site administrators on the risks of using outdated themes and the importance of timely updates. 9. Consider temporarily disabling or replacing the Hygia theme with a secure alternative if immediate patching is not feasible. 10. Implement network segmentation to limit lateral movement if a compromise occurs.