The LambertGroup Famous - Responsive Image And Video Grid Gallery WordPress plugin, up to version 1.4, contains a reflected Cross-site Scripting (XSS) vulnerability identified as CVE-2025-27004. This vulnerability stems from improper neutralization of input during web page generation, specifically failing to sanitize user-supplied data before rendering it in the HTML output. Reflected XSS occurs when malicious scripts are embedded in URLs or input fields and immediately reflected back in the HTTP response, enabling attackers to execute arbitrary JavaScript in the victim's browser. This can lead to session hijacking, theft of cookies or credentials, defacement, or redirection to malicious websites. The vulnerability does not require authentication, increasing its risk profile, and does not currently have a CVSS score or known exploits in the wild. However, the plugin’s widespread use in WordPress sites for image and video galleries makes it a valuable target for attackers. The lack of available patches at the time of publication necessitates urgent attention from site administrators. The vulnerability was reserved in February 2025 and published in January 2026, indicating a window for potential exploitation. The absence of CWE identifiers limits detailed technical classification, but the nature of reflected XSS is well understood in web security contexts.

For European organizations, the impact of this vulnerability can be significant, particularly for those operating public-facing WordPress websites that utilize the affected plugin. Successful exploitation could compromise user sessions, leading to unauthorized access to user accounts or sensitive data. This is especially critical for e-commerce, media, and governmental websites where trust and data confidentiality are paramount. The reflected XSS can also be used as a vector for phishing attacks or malware distribution, damaging organizational reputation and causing regulatory compliance issues under GDPR if personal data is compromised. The vulnerability affects the integrity and confidentiality of web interactions and could disrupt availability if attackers leverage it to deface sites or cause client-side disruptions. Since no authentication is required, attackers can target any visitor, increasing the scope of affected users. The lack of known exploits currently reduces immediate risk but does not eliminate the potential for future attacks, especially as threat actors often weaponize such vulnerabilities rapidly after disclosure.

European organizations should prioritize the following mitigation steps: 1) Monitor the LambertGroup plugin repository and security advisories for official patches and apply them immediately upon release. 2) Until patches are available, consider disabling or replacing the plugin with a secure alternative to eliminate exposure. 3) Implement strict input validation and output encoding on all user-supplied data within the web application to prevent script injection. 4) Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers, mitigating the impact of potential XSS attacks. 5) Conduct regular security audits and penetration testing focused on web application vulnerabilities, including XSS. 6) Educate web administrators and developers about secure coding practices and the risks of reflected XSS. 7) Use Web Application Firewalls (WAFs) configured to detect and block common XSS attack patterns targeting the plugin’s endpoints. 8) Monitor web traffic and logs for suspicious activity indicative of exploitation attempts. These steps, combined, provide a layered defense reducing the likelihood and impact of exploitation.