CVE-2025-41059 is a stored Cross-Site Scripting (XSS) vulnerability identified in appRain CMF version 4.0.5. The vulnerability arises from improper neutralization of user input (CWE-79) in the parameters 'data[Addon][layouts]' and 'data[Addon][layouts_except]' within the endpoint /apprain/developer/addons/update/tablesorter. Specifically, the application fails to adequately validate or sanitize these inputs before incorporating them into web page content, allowing an authenticated user to inject malicious scripts that are stored and later executed in the context of other users or administrators viewing the affected pages. The CVSS 4.0 base score is 5.1 (medium severity), reflecting that the attack vector is network-based (AV:N), requires low attack complexity (AC:L), no privileges (PR:L - low privileges, meaning some authentication is needed), and requires user interaction (UI:P). The vulnerability does not impact confidentiality, integrity, or availability directly but can lead to session hijacking, credential theft, or unauthorized actions via script execution. No known exploits have been reported in the wild as of the publication date (September 2025). The vulnerability is specifically tied to appRain CMF 4.0.5, a content management framework used for web application development, which may be deployed in various organizational environments. The lack of a patch link indicates that a fix may not yet be publicly available, emphasizing the need for mitigation through configuration or access control until a patch is released.

For European organizations using appRain CMF 4.0.5, this vulnerability poses a risk primarily to web application security and user trust. Exploitation could allow attackers with authenticated access to inject malicious scripts that execute in other users' browsers, potentially leading to session hijacking, theft of sensitive data, or unauthorized actions performed on behalf of legitimate users. This can compromise the confidentiality and integrity of user data and may facilitate further attacks such as privilege escalation or lateral movement within the network. Given the authenticated nature of the exploit, insider threats or compromised accounts are the most likely vectors. The impact is heightened in sectors with strict data protection regulations like GDPR, where data breaches can result in significant legal and financial penalties. Additionally, organizations relying on appRain CMF for critical web services or customer-facing portals may suffer reputational damage and operational disruption if the vulnerability is exploited.

1. Immediate mitigation should focus on restricting access to the affected endpoint (/apprain/developer/addons/update/tablesorter) to trusted administrators only, minimizing the number of users with privileges to modify addon layouts. 2. Implement strict input validation and sanitization at the application level for the 'data[Addon][layouts]' and 'data[Addon][layouts_except]' parameters, using context-aware encoding to neutralize any script content. 3. Employ Web Application Firewalls (WAFs) with custom rules to detect and block suspicious payloads targeting these parameters. 4. Monitor logs for unusual activity related to addon updates or unexpected script injections. 5. Until an official patch is released, consider disabling or limiting the use of the vulnerable functionality if feasible. 6. Educate users and administrators about phishing and social engineering risks that could lead to credential compromise, as authenticated access is required for exploitation. 7. Plan for rapid deployment of patches once available and conduct thorough testing to ensure the vulnerability is fully remediated.