CVE-2025-58940 is a vulnerability in the Basil PHP theme developed by axiomthemes, specifically related to improper control over the filename used in PHP include or require statements. This flaw allows an attacker to perform Remote File Inclusion (RFI), a critical security issue where an attacker can supply a remote file path that the application then includes and executes as PHP code. The vulnerability affects all versions of Basil up to and including 1.3.12. The CVSS 3.1 base score is 8.2, reflecting a high severity due to the vulnerability's network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), and no user interaction needed (UI:N). The impact on confidentiality is high because attackers can execute arbitrary code, potentially accessing sensitive data. Integrity impact is low as the attacker can modify execution flow but not necessarily data directly, and availability impact is none. The vulnerability is publicly disclosed as of December 18, 2025, with no known exploits in the wild yet. The root cause is insufficient validation or sanitization of user-controlled input used in include/require statements, allowing malicious remote URLs to be injected and executed. This type of vulnerability is particularly dangerous in PHP environments because it can lead to full system compromise, data theft, or pivoting within the network. The vulnerability is relevant to organizations using the Basil theme in their PHP-based web applications, especially those exposed to the internet without additional protections.

For European organizations, this vulnerability poses a significant risk to web applications using the Basil PHP theme, potentially leading to unauthorized remote code execution. The confidentiality of sensitive data can be severely compromised, including customer information, intellectual property, and internal credentials. Attackers could leverage this vulnerability to implant backdoors, conduct lateral movement, or exfiltrate data. The integrity of the application and its data could be partially affected if attackers modify execution flow or inject malicious scripts. Although availability impact is not directly indicated, secondary effects such as system instability or denial of service could occur if attackers disrupt normal operations. Organizations in sectors with strict data protection regulations, such as finance, healthcare, and government, face heightened compliance risks and potential legal consequences. The ease of exploitation without authentication and user interaction increases the likelihood of automated attacks targeting vulnerable systems. This vulnerability could also be used as an initial access vector in broader cyberattack campaigns targeting European enterprises.

1. Immediately monitor for updates or patches from axiomthemes and apply them as soon as they become available to address the vulnerability directly. 2. In the absence of a patch, implement strict input validation and sanitization on all user-supplied data that may influence include or require statements, ensuring only trusted, local files can be referenced. 3. Disable the PHP allow_url_include directive in the php.ini configuration to prevent inclusion of remote files, which effectively mitigates RFI attacks. 4. Employ web application firewalls (WAFs) with rules designed to detect and block attempts to exploit file inclusion vulnerabilities, including suspicious URL patterns and payloads. 5. Conduct regular code reviews and security audits of custom PHP code and third-party themes/plugins to identify and remediate similar vulnerabilities. 6. Restrict file system permissions to limit the PHP process's ability to access or execute unauthorized files. 7. Monitor web server logs for unusual requests that may indicate exploitation attempts, such as requests containing suspicious URL parameters or remote file paths. 8. Educate development and operations teams about secure coding practices related to file inclusion and input handling to prevent recurrence.