CVE-2025-4760 is a stored cross-site scripting (XSS) vulnerability identified in multiple versions of the WSO2 API Manager, specifically versions 3.2.0 through 4.5.0. This vulnerability arises from improper neutralization of user-supplied input during the API document upload process in the Publisher portal. An authenticated user with publisher privileges can upload a maliciously crafted API document containing embedded JavaScript code. When other users access or view this document through their browsers, the malicious script executes in their context. The vulnerability is classified under CWE-79, which pertains to improper input validation leading to XSS attacks. The attack vector requires network access and low attack complexity but does require the attacker to have publisher-level privileges and some user interaction (viewing the malicious document). The vulnerability impacts confidentiality and integrity by enabling unauthorized UI modifications, redirection to malicious websites, and exfiltration of browser-accessible data. However, session cookies are protected by the httpOnly flag, mitigating session hijacking risks. The CVSS v3.1 base score is 4.8 (medium severity), reflecting limited impact on availability and the requirement for authentication and user interaction. No known exploits are currently reported in the wild, and no official patches have been linked yet. This vulnerability highlights the risk of insufficient input sanitization in web applications that handle document uploads and dynamic content rendering, especially in API management platforms used to govern enterprise APIs.

For European organizations using WSO2 API Manager, this vulnerability poses a moderate risk. The ability for a publisher-level user to inject malicious scripts could lead to unauthorized data exposure within the API management environment, manipulation of the user interface, or redirection of users to phishing or malware sites. While session hijacking is mitigated, the exfiltration of sensitive browser-accessible data (such as tokens or API keys stored in local storage) remains a concern. This could facilitate further lateral movement or privilege escalation within the organization. Given that API management platforms are critical infrastructure components for digital services, exploitation could disrupt API governance, impact developer productivity, and potentially expose sensitive API metadata. The requirement for publisher privileges limits the attack surface to internal or trusted users, but insider threats or compromised accounts could exploit this vulnerability. The lack of known exploits reduces immediate risk, but organizations should act proactively to prevent potential future attacks. The vulnerability's medium severity suggests it should be prioritized alongside other security issues but is not an emergency.

European organizations should implement the following specific mitigations: 1) Restrict publisher privileges strictly to trusted personnel and enforce strong authentication and authorization controls to minimize the risk of malicious uploads. 2) Monitor and audit API document uploads for unusual or suspicious content, employing automated scanning tools to detect embedded scripts or anomalous payloads. 3) Apply strict content security policies (CSP) in the API Manager web interface to limit the execution of inline scripts and reduce the impact of XSS attacks. 4) Regularly update WSO2 API Manager to the latest versions once official patches for CVE-2025-4760 are released. 5) Educate users with publisher roles about safe upload practices and the risks of malicious documents. 6) Implement network segmentation and access controls to limit exposure of the API Manager portal to only necessary users and networks. 7) Consider deploying web application firewalls (WAFs) with custom rules to detect and block malicious script payloads in API document uploads. These measures combined will reduce the likelihood and impact of exploitation beyond generic advice.