CVE-2025-31697 is a Cross-Site Scripting (XSS) vulnerability classified under CWE-79, affecting the Drupal Formatter Suite module versions prior to 2.1.0, specifically from version 0.0.0 up to but not including 2.1.0. The vulnerability arises due to improper neutralization of input during web page generation, allowing malicious actors to inject and execute arbitrary scripts in the context of a victim's browser. This flaw is exploitable remotely over the network (AV:N) without requiring any privileges (PR:N), but it does require user interaction (UI:R), such as clicking a crafted link or visiting a maliciously crafted page. The vulnerability has a CVSS 3.1 base score of 6.1, indicating a medium severity level. The impact primarily affects confidentiality and integrity, as attackers can steal session tokens, manipulate displayed content, or perform actions on behalf of the user, but it does not affect availability. The scope is changed (S:C), meaning the vulnerability can affect components beyond the vulnerable module itself, potentially impacting the entire Drupal site. No known exploits are currently reported in the wild, and no official patches have been linked yet. The vulnerability is specific to the Formatter Suite, a Drupal module commonly used to customize content presentation, which is widely deployed in Drupal-based websites. Given Drupal's popularity in Europe, especially among government, educational, and enterprise sectors, this vulnerability could be leveraged to target users of affected sites, leading to data leakage or session hijacking.

For European organizations, this XSS vulnerability poses a significant risk to web applications built on Drupal that utilize the Formatter Suite module. Exploitation could lead to unauthorized disclosure of sensitive information such as user credentials, personal data, or internal communications, violating GDPR and other data protection regulations. The integrity of displayed content can be compromised, potentially misleading users or damaging organizational reputation. Although availability is not directly impacted, successful exploitation could facilitate further attacks like phishing or privilege escalation. Sectors such as government agencies, financial institutions, educational institutions, and healthcare providers, which often rely on Drupal for their web presence, are at heightened risk. The medium severity score suggests that while the vulnerability is not critical, it is sufficiently serious to warrant prompt attention, especially given the scope change and the potential for widespread impact across interconnected Drupal components.

Organizations should immediately audit their Drupal installations to identify the presence and version of the Formatter Suite module. Until an official patch is released, applying temporary mitigations such as disabling the Formatter Suite module or restricting its usage to trusted administrators can reduce exposure. Implementing Content Security Policy (CSP) headers can help mitigate the impact of XSS by restricting script execution sources. Web Application Firewalls (WAFs) should be configured to detect and block typical XSS payloads targeting Drupal sites. Additionally, input validation and output encoding best practices should be reviewed and enforced within custom Drupal modules or themes. Monitoring web server logs and Drupal security advisories for updates or exploit attempts is critical. Once a patch is available, organizations must prioritize timely updates. For public-facing sites, user education on avoiding suspicious links and enabling multi-factor authentication can further reduce risk.