CVE-2025-48290 is a critical vulnerability identified in the bslthemes Kinsley PHP theme, versions up to and including 3.4.4. The flaw stems from improper control over the filename parameter used in PHP include or require statements, which are functions that incorporate external files into PHP scripts. This improper control allows an attacker to perform Remote File Inclusion (RFI), where a malicious file hosted on an attacker-controlled server can be included and executed on the vulnerable system. This leads to arbitrary code execution, enabling attackers to run commands, steal sensitive data, modify website content, or disrupt service availability. The vulnerability does not require any privileges or user interaction and can be exploited remotely over the network, increasing its severity and ease of exploitation. The CVSS v3.1 base score of 9.8 reflects the critical nature of this vulnerability, with high impact on confidentiality, integrity, and availability. Although no public exploits are currently known, the vulnerability's characteristics make it a prime target for attackers once exploit code becomes available. The vulnerability affects websites and applications using the Kinsley theme, which is popular among PHP-based CMS users. Due to the nature of PHP applications and their widespread use in Europe, this vulnerability poses a significant threat to organizations relying on this theme for their web presence.

The impact of CVE-2025-48290 on European organizations can be severe. Exploitation can lead to complete system compromise, allowing attackers to execute arbitrary code, access sensitive customer and business data, deface websites, or disrupt online services. This can result in financial losses, reputational damage, regulatory penalties under GDPR for data breaches, and operational downtime. Organizations in sectors such as e-commerce, government, education, and media that rely on PHP-based websites with the Kinsley theme are particularly vulnerable. The ease of remote exploitation without authentication increases the risk of widespread attacks. Additionally, compromised systems could be used as a foothold for lateral movement within networks or as part of botnets targeting other entities. The threat is amplified by the critical CVSS score and the lack of currently available patches or mitigations from the vendor, increasing the urgency for organizations to implement defensive measures.

To mitigate CVE-2025-48290, organizations should immediately assess their use of the bslthemes Kinsley theme and upgrade to a patched version once available. In the absence of an official patch, temporary mitigations include disabling or restricting the use of dynamic file inclusion features in PHP configurations and code. Implement strict input validation and sanitization to ensure that user-supplied data cannot influence file paths used in include/require statements. Employ web application firewalls (WAFs) to detect and block attempts to exploit RFI vulnerabilities by filtering suspicious URL parameters or payloads. Conduct thorough code reviews to identify and refactor unsafe file inclusion logic. Additionally, restrict outbound HTTP requests from web servers to prevent fetching remote malicious files. Monitor web server logs for unusual requests that may indicate exploitation attempts. Finally, maintain regular backups and incident response plans to quickly recover from potential compromises.