CVE-2026-24531 is a Remote File Inclusion vulnerability found in the Select-Themes Prowess PHP theme, affecting versions up to 2.3. The vulnerability arises from improper control of the filename parameter used in PHP's include or require statements, allowing an attacker to specify a remote file to be included and executed by the server. This flaw enables unauthenticated remote attackers to execute arbitrary PHP code on the affected server, potentially leading to full system compromise. The vulnerability is classified as critical with a CVSS v3.1 score of 9.8, reflecting its high impact and ease of exploitation (network vector, no privileges or user interaction required). The attack surface includes any web server running the vulnerable Prowess theme, commonly used in WordPress or similar PHP-based CMS environments. Exploitation could result in data theft, website defacement, malware deployment, or pivoting to internal networks. Although no public exploits are currently documented, the vulnerability's nature and severity make it a prime target for attackers once exploit code becomes available. The lack of a vendor patch at the time of disclosure increases the urgency for interim mitigations. This vulnerability highlights the risks of insecure coding practices in PHP applications, particularly around dynamic file inclusion without proper validation or sanitization.

For European organizations, exploitation of CVE-2026-24531 could lead to severe consequences including unauthorized access to sensitive customer and business data, disruption of online services, reputational damage, and potential regulatory penalties under GDPR due to data breaches. Organizations relying on the Select-Themes Prowess theme for their websites or web applications face risks of remote code execution, which could allow attackers to implant backdoors, steal credentials, or launch further attacks within corporate networks. The critical nature of the vulnerability means that even small or medium enterprises using this theme could be compromised rapidly. Additionally, public sector entities and critical infrastructure providers using PHP-based web platforms are at heightened risk due to the potential for service disruption and data exposure. The vulnerability could also be leveraged in supply chain attacks if exploited on widely used web platforms. The absence of known exploits currently provides a window for proactive defense, but the high CVSS score signals that attackers will likely develop exploits quickly.

1. Immediately audit all web servers and CMS installations for the presence of the Select-Themes Prowess theme version 2.3 or earlier. 2. Disable or remove the vulnerable theme until a vendor patch is released. 3. Monitor vendor channels and security advisories for official patches and apply them promptly once available. 4. Implement Web Application Firewalls (WAFs) with rules to detect and block Remote File Inclusion attempts, focusing on suspicious include/require parameter manipulations. 5. Harden PHP configurations by disabling allow_url_include and allow_url_fopen directives to prevent remote file inclusion. 6. Conduct code reviews and penetration testing on custom PHP applications to detect similar insecure file inclusion patterns. 7. Employ network segmentation to limit the impact of a compromised web server. 8. Maintain regular backups and incident response plans to quickly recover from potential compromises. 9. Educate development teams on secure coding practices, especially validating and sanitizing all user inputs used in file operations. 10. Use security scanners to detect vulnerable themes and plugins in CMS environments continuously.