CVE-2025-66102 identifies a reflected Cross-site Scripting (XSS) vulnerability in the FolioVision FV Antispam plugin, a tool commonly used to reduce spam on WordPress websites. The vulnerability stems from improper neutralization of user-supplied input during the generation of web pages, which allows attackers to inject malicious JavaScript code that is reflected back to users without adequate sanitization. When a victim visits a crafted URL or interacts with a manipulated web page, the injected script executes in their browser context. This can lead to various malicious outcomes including theft of session cookies, redirection to malicious sites, or execution of unauthorized actions under the victim’s credentials. The affected versions include all releases up to and including version 2.7, with no patch currently available or linked. The vulnerability was reserved and published in late 2025, and no exploits have been observed in the wild so far. The lack of a CVSS score requires an independent severity assessment. The vulnerability does not require user authentication but does require victim interaction (clicking a malicious link or visiting a compromised page). The plugin’s widespread use in WordPress sites, especially in Europe where WordPress dominates the CMS market, increases the potential attack surface. The vulnerability’s exploitation could compromise website visitors and administrators, impacting confidentiality and integrity of data and potentially availability if leveraged in chained attacks.

For European organizations, the impact of CVE-2025-66102 could be significant, especially for those relying on WordPress websites with the FV Antispam plugin installed. Exploitation could lead to unauthorized access to user sessions, enabling attackers to impersonate users or administrators, steal sensitive information, or conduct phishing attacks. This is particularly critical for e-commerce platforms, government portals, and financial services websites where user trust and data confidentiality are paramount. The reflected XSS can also facilitate the spread of malware or redirect users to malicious sites, damaging organizational reputation and potentially causing regulatory compliance issues under GDPR. The absence of a patch increases the window of exposure, making timely mitigation essential. Additionally, the vulnerability could be used as a stepping stone for more complex attacks, such as privilege escalation or persistent cross-site scripting if combined with other vulnerabilities.

1. Monitor FolioVision’s official channels for patches and apply updates immediately once available. 2. Until a patch is released, implement Web Application Firewall (WAF) rules to detect and block typical XSS attack patterns targeting the FV Antispam plugin. 3. Employ strict input validation and output encoding on all user-supplied data, especially URL parameters and form inputs processed by the plugin. 4. Conduct regular security audits and penetration testing focused on XSS vulnerabilities in web applications using FV Antispam. 5. Educate website administrators and users about the risks of clicking untrusted links and encourage use of security headers like Content Security Policy (CSP) to mitigate script injection impacts. 6. Consider temporarily disabling the FV Antispam plugin if the risk is deemed unacceptable and no immediate patch is available, replacing it with alternative anti-spam solutions that are verified secure. 7. Review and harden session management and authentication mechanisms to limit damage from stolen credentials or session tokens.