CVE-2025-14556 is a Cross-Site Scripting (XSS) vulnerability identified in the Drupal Flag module, specifically affecting versions from 7.x-3.0 through 7.x-3.9. The root cause is improper neutralization of input during web page generation, categorized under CWE-79. This flaw allows attackers to inject malicious scripts into web pages viewed by other users. The vulnerability has a CVSS 4.0 base score of 4.8, indicating medium severity. The attack vector is network-based (AV:N), with low attack complexity (AC:L), requiring no privileges (PR:L) but does require user interaction (UI:A). The vulnerability does not compromise confidentiality, integrity, or availability directly (VC:N, VI:N, VA:N), but the scope is limited (SC:L) and impacts integrity (SI:L). Exploiting this vulnerability could enable attackers to execute arbitrary JavaScript in the context of the victim’s browser, potentially leading to session hijacking, phishing, or unauthorized actions on behalf of the user. Although no known exploits are currently reported in the wild, the widespread use of Drupal in web content management makes this a relevant threat. The absence of patches at the time of reporting necessitates proactive mitigation. The vulnerability affects Drupal Flag, a module used to add flagging functionality to Drupal sites, which is commonly used in community-driven or content-heavy websites. The vulnerability was reserved in December 2025 and published in January 2026, indicating recent discovery and disclosure.

For European organizations, the impact of CVE-2025-14556 can be significant, especially for those relying on Drupal-based websites for public-facing services, e-commerce, or community engagement platforms. Successful exploitation could lead to unauthorized script execution in users’ browsers, resulting in session hijacking, theft of sensitive user data, or redirection to malicious websites. This undermines user trust and can lead to reputational damage, regulatory scrutiny under GDPR for data protection failures, and potential financial losses. Organizations in sectors such as government, healthcare, finance, and media that use Drupal Flag are particularly at risk due to the sensitivity of their data and the critical nature of their services. The vulnerability’s requirement for user interaction means phishing or social engineering could be used to trigger the exploit, increasing the attack surface. Although the vulnerability does not directly affect system availability, the indirect consequences of compromised user sessions or defaced websites can disrupt normal operations and service delivery.

1. Monitor official Drupal security advisories for patches addressing CVE-2025-14556 and apply them promptly once released. 2. Until patches are available, implement strict input validation and sanitization on all user-supplied data within the Drupal Flag module context to reduce injection risk. 3. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and mitigate the impact of potential XSS payloads. 4. Educate users and administrators about phishing risks and the importance of cautious interaction with untrusted links or content. 5. Conduct regular security audits and penetration testing focused on web application vulnerabilities, including XSS. 6. Utilize web application firewalls (WAFs) configured to detect and block common XSS attack patterns targeting Drupal sites. 7. Review and limit the use of the Drupal Flag module to only necessary instances and consider alternative modules with better security track records if feasible. 8. Maintain up-to-date backups of affected websites to enable rapid recovery in case of compromise.