CVE-2025-53435 is a vulnerability classified as Improper Control of Filename for Include/Require Statement in the PHP program 'Plan My Day' theme developed by axiomthemes. This vulnerability allows Remote File Inclusion (RFI), where an attacker can manipulate the filename parameter used in PHP include or require statements to load and execute malicious PHP code from a remote server. The affected versions are all up to and including 1.1.13. The root cause is insufficient validation or sanitization of user-supplied input that controls the file path in include/require functions. When exploited, this can lead to arbitrary code execution on the web server, enabling attackers to take control of the affected system, access sensitive data, modify website content, or pivot to internal networks. No CVSS score has been assigned yet, and no public exploits are known at this time. The vulnerability was reserved in June 2025 and published in December 2025. The lack of patch links suggests that a fix may not yet be available, increasing the urgency for interim mitigations. Since the vulnerability targets a PHP theme, it primarily affects websites running PHP environments with this theme installed, commonly WordPress or similar CMS platforms. The attack vector is remote and does not require authentication, making it easier for attackers to exploit if the vulnerable theme is publicly accessible.

For European organizations, the impact of CVE-2025-53435 can be significant. Many European businesses rely on PHP-based CMS platforms like WordPress, where themes such as Plan My Day are used to manage website appearance and functionality. Exploitation could lead to unauthorized access to sensitive customer data, intellectual property theft, website defacement, or use of compromised servers as launchpads for further attacks. This can damage brand reputation, lead to regulatory penalties under GDPR for data breaches, and disrupt business operations. Sectors such as e-commerce, finance, healthcare, and government agencies are particularly vulnerable due to their reliance on web applications and the sensitivity of their data. The vulnerability’s remote exploitation capability without authentication increases the risk of widespread attacks. Additionally, the lack of an available patch at the time of disclosure means organizations must rely on mitigations to reduce exposure, increasing operational complexity and risk.

1. Immediately audit all web servers for the presence of the Plan My Day theme version 1.1.13 or earlier and remove or disable it if not essential. 2. Monitor web server logs for suspicious requests attempting to manipulate include or require parameters, especially those containing URL or file path traversal patterns. 3. Implement strict input validation and sanitization on any user-controlled parameters that influence file inclusion. 4. Configure PHP settings to disable remote file inclusion by setting 'allow_url_include' to 'Off' and 'allow_url_fopen' to 'Off' where feasible. 5. Employ Web Application Firewalls (WAFs) with rules designed to detect and block RFI attack patterns targeting PHP include statements. 6. Segregate web server environments and limit permissions to reduce the impact of potential code execution. 7. Stay alert for official patches or updates from axiomthemes and apply them promptly once released. 8. Conduct regular security assessments and penetration testing focused on file inclusion vulnerabilities. 9. Educate development and operations teams about secure coding practices to prevent similar vulnerabilities in custom themes or plugins.