CVE-2025-10926 is a vulnerability classified under CWE-79, indicating improper neutralization of input leading to Cross-Site Scripting (XSS) in the Drupal JSON Field module. This module, used to handle JSON data within Drupal content management systems, fails to properly sanitize or encode user-supplied input before rendering it on web pages. As a result, attackers can inject malicious JavaScript code that executes in the context of users' browsers visiting the affected Drupal site. Such XSS attacks can be leveraged to steal session cookies, perform actions on behalf of authenticated users, or redirect users to malicious sites. The vulnerability affects all versions of the JSON Field module before 1.5, with no patch links currently available, indicating that a fix is either pending or recently released but not linked. Although no known exploits are reported in the wild, the nature of XSS vulnerabilities makes them attractive targets for attackers due to their relative ease of exploitation and potential for significant impact. The vulnerability was reserved in late September 2025 and published in late October 2025, suggesting recent discovery. The absence of a CVSS score requires an independent severity assessment based on the vulnerability's characteristics and potential impact.

For European organizations, the impact of this vulnerability can be significant, particularly for those using Drupal as their web content management system with the JSON Field module enabled. Successful exploitation can compromise the confidentiality of user data by stealing session tokens or credentials, leading to unauthorized access. Integrity can be affected if attackers perform unauthorized actions or inject misleading content. Availability is less directly impacted but could be affected if attackers use the vulnerability to conduct phishing or social engineering campaigns that disrupt user trust. Public sector websites, e-commerce platforms, and service portals in Europe that rely on Drupal are at risk of reputational damage, regulatory penalties under GDPR for data breaches, and operational disruptions. The lack of known exploits currently provides a window for proactive mitigation, but the ease of exploitation typical of XSS vulnerabilities means rapid patching is critical to prevent future attacks.

European organizations should immediately inventory their Drupal installations to identify the use of the JSON Field module and its version. They should plan to upgrade the module to version 1.5 or later as soon as it becomes available, ensuring that the vulnerability is patched. In the interim, organizations can implement web application firewalls (WAFs) with rules designed to detect and block common XSS attack patterns targeting JSON payloads. Additionally, enforcing Content Security Policy (CSP) headers can help mitigate the impact of injected scripts by restricting script execution sources. Developers should review and enhance input validation and output encoding practices, particularly for JSON data rendered in web pages. Regular security audits and penetration testing focusing on XSS vulnerabilities are recommended. Monitoring for suspicious activity and user reports of unusual behavior on affected sites can provide early warning of exploitation attempts.