CVE-2025-13083 is a security vulnerability identified in the Drupal core content management system affecting multiple versions starting from 8.0.0 through various 10.x and 11.x releases prior to specific patch versions. The issue stems from the improper handling of web browser cache, where sensitive information is stored and accessible due to incorrectly configured access control security levels within Drupal. This misconfiguration allows sensitive data, potentially including session tokens, user credentials, or other confidential information, to be cached by the browser and subsequently accessed by unauthorized users who can reach the victim's browser cache. The vulnerability is categorized under CWE-525, which relates to the use of web browser cache containing sensitive information. The CVSS v3.1 base score is 3.7 (low), with vector AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N, indicating that the attack can be performed remotely over the network without privileges or user interaction but requires high attack complexity. The vulnerability does not impact integrity or availability, only confidentiality. No known exploits have been reported in the wild as of the publication date. The vulnerability affects a broad range of Drupal core versions, highlighting the importance of updating to the fixed releases (10.4.9, 10.5.6, 11.1.9, 11.2.8 or later).

For European organizations, the primary impact of CVE-2025-13083 is the potential leakage of sensitive information through the web browser cache. This can lead to unauthorized disclosure of confidential data, which may include user session information or other private content served by Drupal-based websites. While the vulnerability does not allow modification or disruption of services, the confidentiality breach could facilitate further attacks such as session hijacking or identity theft. Organizations operating public-facing Drupal websites, especially those handling personal data under GDPR, face compliance risks if sensitive data is exposed. The low CVSS score suggests limited direct damage, but the risk of data leakage remains a concern, particularly for sectors like government, finance, healthcare, and e-commerce where Drupal is widely used. The absence of known exploits reduces immediate threat levels, but proactive patching is essential to mitigate potential future exploitation.

European organizations should immediately assess their Drupal core versions and upgrade to the patched releases: 10.4.9, 10.5.6, 11.1.9, 11.2.8, or later. Beyond patching, administrators should review and harden access control configurations to ensure sensitive data is not cached in browsers. Implement HTTP headers such as Cache-Control: no-store and Pragma: no-cache on sensitive pages to prevent caching of confidential information. Conduct regular security audits focusing on web application caching policies and session management. Employ Content Security Policy (CSP) to restrict resource loading and reduce attack surface. Educate developers and administrators about secure caching practices and monitor web traffic for unusual access patterns that may indicate attempts to exploit cached data. Finally, ensure compliance with GDPR data protection requirements by minimizing sensitive data exposure and documenting mitigation efforts.