CVE-2025-53453 is a Remote File Inclusion (RFI) vulnerability affecting the axiomthemes Hygia WordPress theme versions up to and including 1.16. The vulnerability stems from improper validation and control of filenames used in PHP include or require statements. This flaw allows an attacker to supply a crafted URL or filename parameter that causes the application to include and execute remote PHP code hosted on an attacker-controlled server. The vulnerability requires no authentication or user interaction and can be exploited remotely over the network. Successful exploitation can lead to arbitrary code execution, resulting in full compromise of confidentiality (e.g., data theft) and partial compromise of integrity (e.g., code or content manipulation). The vulnerability does not directly impact availability but could be leveraged to disrupt services indirectly. The CVSS v3.1 score of 8.2 reflects the ease of exploitation (network vector, no privileges, no user interaction) and the high impact on confidentiality. No patches or fixes are currently linked, and no known exploits have been reported in the wild as of the publication date. The vulnerability affects all installations of the Hygia theme up to version 1.16, which is used primarily in WordPress environments.

For European organizations, this vulnerability poses a significant risk, especially for those using the Hygia WordPress theme on public-facing websites. Exploitation could lead to unauthorized disclosure of sensitive data, including customer information and internal business data, undermining confidentiality. Partial integrity loss could allow attackers to modify website content or inject malicious scripts, potentially damaging brand reputation and enabling further attacks such as phishing or malware distribution. Although availability is not directly affected, secondary impacts such as website defacement or backdoor installation could disrupt business operations. Organizations in sectors with strict data protection regulations (e.g., GDPR) face additional legal and compliance risks if breaches occur. The lack of authentication requirement and ease of exploitation increase the likelihood of opportunistic attacks. The threat is particularly relevant for SMEs and enterprises relying on WordPress themes without rigorous security controls or patch management.

Organizations should immediately assess their WordPress installations to determine if the Hygia theme version 1.16 or earlier is in use. If so, they should prioritize upgrading to a patched version once available or temporarily disable the theme to prevent exploitation. In the absence of an official patch, applying web application firewall (WAF) rules to block suspicious include or require parameters can mitigate exploitation attempts. Restricting outbound HTTP requests from the web server can prevent remote file inclusion by blocking access to attacker-controlled servers. Implementing strict input validation and sanitization on any user-controllable parameters related to file inclusion is critical. Regularly monitoring web server logs for unusual requests targeting include/require parameters can aid early detection. Additionally, organizations should ensure that PHP configurations disable allow_url_include and allow_url_fopen directives to reduce RFI risks. Conducting security audits and penetration testing focused on theme vulnerabilities can help identify residual risks.