CVE-2025-43800 is a Cross-site Scripting (XSS) vulnerability identified in Liferay Portal versions 7.4.3.20 through 7.4.3.111 and Liferay DXP versions 2023.Q4.0, 2023.Q3.1 through 2023.Q3.4, and 7.4 GA through update 92. The vulnerability arises from improper neutralization of input during web page generation, specifically within objects that contain rich text type fields. An attacker can exploit this flaw by injecting crafted malicious scripts or HTML payloads into these rich text fields. When other users or administrators view the affected content, the malicious script executes in their browsers, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim. The vulnerability requires low privileges (PR:L) and user interaction (UI:A) to be exploited, but does not require authentication (AT:N) or elevated privileges. The CVSS 4.0 base score is 4.8, indicating a medium severity level. The attack vector is network-based (AV:N), and the vulnerability impacts the confidentiality and integrity of the affected systems to a limited extent (VC:L, VI:L). No known exploits are currently reported in the wild, and no patches have been linked yet. This vulnerability is classified under CWE-79, which is a common and well-understood category of web application security issues related to improper input sanitization and output encoding.

For European organizations using Liferay Portal or Liferay DXP, this vulnerability poses a moderate risk. Liferay is widely used in enterprise content management, intranet portals, and customer-facing web applications across various sectors including government, education, and private enterprises. Exploitation of this XSS vulnerability could allow attackers to execute malicious scripts in the context of legitimate users, potentially leading to session hijacking, data leakage, or unauthorized actions within the portal environment. This could compromise sensitive organizational data, disrupt business operations, and damage trust with customers or partners. Given the medium severity and the requirement for user interaction, the impact is significant but not critical. However, if exploited in environments with sensitive data or privileged users, the consequences could escalate. Additionally, the lack of currently known exploits provides a window for proactive mitigation before widespread attacks occur.

European organizations should implement the following specific mitigation strategies: 1) Immediately review and restrict the use of rich text fields in Liferay objects to trusted users only, minimizing exposure to untrusted input. 2) Apply strict input validation and output encoding on all user-supplied content, particularly in rich text fields, to neutralize potentially malicious scripts. 3) Monitor and audit portal content changes for suspicious payloads or anomalous behavior. 4) Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers accessing the portal. 5) Educate users about the risks of interacting with untrusted content within the portal. 6) Stay alert for official patches or updates from Liferay and apply them promptly once available. 7) Consider deploying web application firewalls (WAFs) with rules tailored to detect and block XSS payloads targeting Liferay portals. These measures go beyond generic advice by focusing on the specific vector (rich text fields) and leveraging layered defenses to reduce risk.