CVE-2025-43812 is a cross-site scripting (XSS) vulnerability identified in Liferay Portal versions 7.4.3.4 through 7.4.3.111, as well as multiple versions of Liferay DXP including 2023.Q4.0 through 2023.Q4.4, 2023.Q3.1 through 2023.Q3.8, and 7.4 GA through update 92. The vulnerability arises from insufficient input sanitization in the web content template feature, specifically in the 'Name' text field of a web content structure. Remote authenticated users with at least limited privileges can inject arbitrary HTML or JavaScript code by crafting malicious payloads into this field. When other users view the affected content, the injected script executes in their browsers, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim user. The CVSS 4.0 base score is 4.8, indicating a medium severity level. The vector indicates network attack vector, low attack complexity, no privileges required beyond authenticated access, and user interaction is required for exploitation. The vulnerability affects confidentiality and integrity partially, with limited impact on availability. No known exploits are currently reported in the wild, and no patches are linked in the provided data, suggesting that remediation may require vendor updates or configuration changes once available. The vulnerability is classified under CWE-79, which is a common and well-understood web application security issue related to improper neutralization of input leading to XSS.

For European organizations using Liferay Portal or Liferay DXP, this vulnerability poses a risk primarily to web applications that rely on these platforms for content management and portal services. Successful exploitation could allow attackers to execute malicious scripts in the context of authenticated users, potentially leading to theft of session tokens, unauthorized actions, or distribution of malware through the portal. This can result in data breaches, reputational damage, and compliance violations under regulations such as GDPR, especially if personal data is exposed or manipulated. The requirement for authenticated access limits the attack surface to internal or trusted users, but insider threats or compromised accounts could be leveraged. The medium severity suggests moderate risk, but the widespread use of Liferay in European public and private sectors, including government portals and enterprise intranets, increases the potential impact. Additionally, the need for user interaction means social engineering or phishing could be used to trigger the exploit. The vulnerability could also be chained with other exploits to escalate privileges or move laterally within networks.

European organizations should implement the following specific mitigations: 1) Immediately audit and restrict permissions for users who can create or edit web content structures, minimizing the number of users with such privileges. 2) Apply strict input validation and output encoding on the 'Name' field and other user-controllable inputs in Liferay Portal configurations, if possible via custom filters or web application firewalls (WAFs) until official patches are released. 3) Monitor portal logs for unusual content changes or injection attempts, and implement anomaly detection to identify suspicious activity. 4) Educate users about the risks of interacting with untrusted content and implement security awareness training focused on phishing and social engineering. 5) Once vendor patches or updates become available, prioritize their deployment in all affected environments. 6) Consider deploying Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in the portal web pages. 7) Regularly review and update authentication and session management controls to reduce the risk of session hijacking.