CVE-2025-43776 is a medium severity vulnerability affecting multiple versions of Liferay Portal and Liferay DXP, specifically versions 7.4.0 through 7.4.3.132 and various 2024 and 2025 quarterly releases up to 2025.Q2.9. The vulnerability is classified under CWE-209, which involves the generation of error messages containing sensitive information. However, the core issue here is a stored cross-site scripting (XSS) vulnerability that arises from improper sanitization and escaping of user input in the Custom Object field label within the Process Builder's Configuration tab. An authenticated remote attacker with high privileges can inject malicious JavaScript payloads into these field labels. Because the payload is stored, it will be executed whenever the affected configuration interface is accessed, potentially allowing persistent XSS attacks. The CVSS 4.0 vector indicates the attack is network exploitable (AV:N), requires low attack complexity (AC:L), no privileges (PR:H) but with user interaction (UI:A), and results in low confidentiality and integrity impact but no availability impact. The vulnerability does not appear to have known exploits in the wild yet, and no patches are linked in the provided data, suggesting that remediation may require vendor updates or configuration changes. The vulnerability's exploitation requires authenticated access with high privileges, limiting the attack surface to users who already have significant access to the system. Nonetheless, the stored XSS can lead to session hijacking, privilege escalation, or other malicious actions within the context of the Liferay Portal management interface.

For European organizations using Liferay Portal or Liferay DXP, this vulnerability poses a risk primarily to administrative users who have authenticated access to the Process Builder configuration. Exploitation could allow attackers to execute arbitrary JavaScript in the context of the portal's management interface, potentially leading to theft of session tokens, unauthorized actions, or further compromise of the portal environment. Given that Liferay is widely used in enterprise content management, intranet portals, and customer-facing web applications across Europe, exploitation could disrupt business operations, leak sensitive organizational data, or facilitate lateral movement within corporate networks. The impact is heightened in sectors with stringent data protection requirements such as finance, healthcare, and government, where unauthorized access or data leakage can have regulatory and reputational consequences. However, the requirement for authenticated high-privilege access and user interaction reduces the likelihood of widespread exploitation, making targeted attacks against privileged insiders or compromised accounts the most probable threat scenario.

Organizations should immediately review user access controls to ensure that only trusted personnel have high-privilege authenticated access to the Liferay Portal Process Builder configuration. Implement strict role-based access control (RBAC) and monitor for unusual administrative activity. Since no patch links are provided, organizations should consult Liferay's official security advisories for updates or hotfixes addressing CVE-2025-43776. In the interim, consider disabling or restricting access to the Process Builder's Configuration tab for non-essential users. Employ web application firewalls (WAFs) with custom rules to detect and block suspicious JavaScript payloads in input fields. Additionally, conduct regular security assessments and code reviews focusing on input validation and output encoding to prevent stored XSS. Educate administrators about phishing and social engineering risks that could lead to credential compromise, as the vulnerability requires authenticated access. Finally, implement comprehensive logging and alerting to detect potential exploitation attempts promptly.