CVE-2025-43826 is a stored cross-site scripting (XSS) vulnerability identified in Liferay Portal and Liferay DXP products, specifically impacting versions 7.4.0 through 7.4.3.112 for Portal and multiple 2023 Q3 and Q4 releases for DXP. The vulnerability stems from improper neutralization of input during web page generation (CWE-79), allowing attackers to inject arbitrary HTML or JavaScript code into rich text fields within web content articles. When a victim views the compromised content, the malicious script executes in their browser context, potentially leading to session hijacking, credential theft, or unauthorized actions on behalf of the user. The vulnerability does not require authentication to exploit but does require user interaction to trigger the payload. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:L) but user interaction needed (UI:A), and low impact on confidentiality, integrity, and availability (VC:L, VI:L, VA:L). No known exploits have been reported in the wild, and no official patches or updates have been linked at the time of publication. The vulnerability affects both supported and older unsupported versions, increasing the attack surface for organizations that have not updated their Liferay installations. Given Liferay's widespread use in enterprise content management and portal solutions, this vulnerability poses a risk to organizations relying on these platforms for internal and external communications.

For European organizations, this vulnerability could lead to significant security risks including unauthorized access to user sessions, theft of sensitive information, and potential defacement or manipulation of web content. Organizations using Liferay Portal for intranet, extranet, or public-facing websites may experience reputational damage and operational disruption if attackers exploit this XSS flaw. The medium CVSS score reflects moderate impact, but the ease of exploitation and the widespread use of Liferay in sectors such as government, finance, and healthcare in Europe elevate the risk. Attackers could leverage this vulnerability to conduct phishing campaigns, spread malware, or gain footholds for further network intrusion. The lack of authentication requirement lowers the barrier for exploitation, making it accessible to a broader range of threat actors. Additionally, stored XSS vulnerabilities are persistent and can affect multiple users over time, increasing the potential damage. The absence of known exploits currently provides a window for proactive mitigation before widespread attacks occur.

European organizations should immediately audit their Liferay Portal and DXP installations to identify affected versions and plan upgrades to patched releases once available. In the interim, implement strict input validation and sanitization on all rich text fields used in web content translation to prevent malicious script injection. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS payloads. Enable web application firewalls (WAFs) with rules tailored to detect and block XSS attack patterns targeting Liferay portals. Conduct regular security awareness training for users to recognize and avoid interacting with suspicious content. Monitor logs and user activity for anomalies indicative of exploitation attempts. Consider isolating or restricting access to content management interfaces to trusted networks or VPNs to reduce exposure. Engage with Liferay support channels for updates and patches, and subscribe to vulnerability advisories to stay informed. Finally, perform penetration testing focused on XSS vectors in Liferay environments to validate the effectiveness of mitigations.