CVE-2025-39468 is a critical Remote File Inclusion (RFI) vulnerability found in the pantherius Modal Survey PHP application, specifically affecting versions up to and including 2.0.2.0.1. The vulnerability stems from improper control over the filename parameter used in PHP include or require statements, which allows an attacker to supply a remote URL or file path that the application will include and execute. This lack of input validation or sanitization enables unauthenticated attackers to execute arbitrary PHP code on the server remotely. The vulnerability is classified as critical with a CVSS v3.1 score of 9.8, reflecting its network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). Exploiting this vulnerability could lead to full system compromise, including data theft, defacement, or deployment of malware. Although no public exploits have been reported yet, the nature of RFI vulnerabilities and their historical exploitation patterns make this a high-risk issue. The vulnerability affects the Modal Survey product by pantherius, a PHP-based survey tool, which is commonly deployed in web environments. The improper control of include/require filenames is a classic PHP security flaw often mitigated by disabling allow_url_include in PHP configurations and implementing strict input validation. The vulnerability was reserved in April 2025 and published in November 2025, indicating recent discovery and disclosure. No patches or fixes are currently linked, so users must monitor vendor updates closely.

For European organizations, this vulnerability poses a severe risk due to the potential for remote code execution without authentication. Attackers could leverage this flaw to gain unauthorized access to sensitive data, disrupt services, or pivot within the network to compromise additional systems. Organizations running Modal Survey on public-facing web servers are particularly vulnerable to exploitation, which could lead to data breaches involving personal or business-critical information. The impact extends to regulatory compliance, as breaches involving personal data could violate GDPR requirements, leading to legal and financial penalties. Additionally, compromised systems could be used as launchpads for further attacks, including ransomware or supply chain compromises. The availability of the affected application in various sectors such as marketing, customer feedback, and research increases the attack surface. The critical severity and ease of exploitation mean that attackers do not require sophisticated skills or insider access, increasing the likelihood of opportunistic attacks targeting European entities.

Immediate mitigation steps include disabling the PHP configuration directive allow_url_include to prevent remote file inclusion via URLs. Organizations should implement strict input validation and sanitization on all parameters used in include or require statements, ensuring only trusted and local files are referenced. Employing web application firewalls (WAFs) with rules to detect and block suspicious file inclusion attempts can provide additional protection. Monitoring logs for unusual include paths or remote file access attempts is critical for early detection. Until an official patch is released by pantherius, consider isolating or temporarily disabling the Modal Survey application if feasible. Conduct thorough code reviews to identify and remediate similar insecure coding patterns. Educate developers on secure PHP coding practices to prevent recurrence. Finally, maintain up-to-date backups and incident response plans to minimize damage in case of successful exploitation.