CVE-2025-58925 identifies a Remote File Inclusion (RFI) vulnerability in the axiomthemes Neptunus WordPress theme, affecting versions up to 1.0.11. The vulnerability stems from improper validation and control over the filename parameter used in PHP include or require statements. This flaw allows an attacker to manipulate the input to include remote files, which can contain malicious PHP code. When the vulnerable code executes the include or require statement with attacker-controlled input, it results in remote code execution on the web server hosting the WordPress site. This can lead to full compromise of the website, data theft, defacement, or pivoting to internal networks. The vulnerability is particularly dangerous because it does not require authentication or user interaction, making exploitation straightforward if the vulnerable endpoint is exposed. Although no public exploits have been reported yet, the nature of RFI vulnerabilities historically leads to rapid exploitation once disclosed. The affected product is the Neptunus theme by axiomthemes, a WordPress theme used to build websites. The vulnerability affects all versions up to and including 1.0.11, with no patch currently available as per the provided data. The issue was reserved in September 2025 and published in December 2025. The lack of a CVSS score requires an independent severity assessment based on impact and exploitability factors.

For European organizations, this vulnerability poses a significant risk to websites using the Neptunus theme, particularly those hosting sensitive or business-critical information. Successful exploitation can lead to remote code execution, allowing attackers to take full control of the affected web server. This compromises confidentiality, integrity, and availability of the hosted data and services. Attackers could deploy web shells, steal customer data, inject malware, or use the compromised server as a pivot point for further attacks within the corporate network. Given the widespread use of WordPress in Europe, especially in countries with large digital economies such as Germany, France, and the UK, the potential impact is substantial. Organizations in sectors like e-commerce, government, and media that rely on WordPress themes are especially vulnerable. The lack of authentication or user interaction needed for exploitation increases the risk of automated attacks and mass scanning by threat actors. Additionally, the absence of a patch at the time of disclosure means organizations must rely on temporary mitigations, increasing exposure time.

1. Immediate mitigation involves disabling or restricting the vulnerable include/require functionality in the theme's PHP code by implementing strict input validation and sanitization to ensure only safe, local files can be included. 2. Monitor web server logs for suspicious requests attempting to include remote files or unusual URL parameters. 3. Employ Web Application Firewalls (WAFs) with custom rules to block requests containing suspicious file inclusion patterns or external URLs in parameters. 4. Isolate WordPress installations in segmented network zones to limit lateral movement if compromised. 5. Regularly back up website data and configurations to enable rapid restoration in case of compromise. 6. Once available, promptly apply official patches or updates from axiomthemes addressing this vulnerability. 7. Consider temporarily switching to a different theme or disabling the Neptunus theme until a fix is released. 8. Educate web administrators about the risks of RFI vulnerabilities and safe coding practices to prevent similar issues in custom themes or plugins.