CVE-2025-41046 is a stored Cross-Site Scripting (XSS) vulnerability identified in version 4.0.5 of the appRain CMF (Content Management Framework). This vulnerability arises due to improper neutralization of user input during web page generation, specifically involving the 'data[Addon][layouts]' and 'data[Addon][layouts_except]' parameters within the endpoint /apprain/developer/addons/update/960grid. Because these parameters are not properly validated or sanitized, an authenticated attacker can inject malicious scripts that are stored on the server and subsequently executed in the browsers of users who access the affected pages. The vulnerability requires low privileges (authenticated user) and some user interaction, but does not require complex attack conditions or advanced authentication bypass. The CVSS 4.0 score is 5.1 (medium severity), reflecting the network attack vector, low attack complexity, no privileges required beyond authentication, and partial user interaction. The vulnerability impacts confidentiality, integrity, and availability to a limited extent, primarily through potential session hijacking, defacement, or redirection attacks. No known exploits in the wild have been reported as of the publication date, and no official patches or mitigations have been linked yet. The vulnerability is classified under CWE-79, which covers improper input neutralization leading to XSS attacks, a common and impactful web security issue.

For European organizations using appRain CMF version 4.0.5, this vulnerability poses a moderate risk. Stored XSS can lead to session hijacking, credential theft, unauthorized actions on behalf of users, and defacement of web content. In sectors such as finance, healthcare, government, and critical infrastructure, these impacts can result in data breaches, loss of user trust, regulatory non-compliance (e.g., GDPR violations), and reputational damage. Since the vulnerability requires authenticated access, insider threats or compromised user accounts could be leveraged to exploit it. The ability to inject persistent scripts could also facilitate phishing campaigns or malware distribution targeting European users. Given the widespread adoption of web-based CMS platforms in Europe, organizations relying on appRain CMF for content management or web application delivery should consider the risk significant enough to warrant immediate attention, especially in industries with high regulatory scrutiny and data sensitivity.

To mitigate this vulnerability effectively, European organizations should: 1) Immediately audit their use of appRain CMF version 4.0.5 and identify any instances of the affected endpoints and parameters. 2) Restrict access to the /apprain/developer/addons/update/960grid endpoint to only highly trusted administrators and monitor access logs for suspicious activity. 3) Implement strict input validation and output encoding on the 'data[Addon][layouts]' and 'data[Addon][layouts_except]' parameters, ensuring that any user-supplied data is sanitized to prevent script injection. 4) Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in browsers. 5) Enforce multi-factor authentication (MFA) for all users with access to the vulnerable functionality to reduce the risk of account compromise. 6) Monitor for unusual user behavior or signs of exploitation, such as unexpected script execution or anomalous HTTP requests. 7) Engage with the appRain vendor or community to obtain patches or updates as soon as they become available and apply them promptly. 8) Consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block malicious payloads targeting these parameters until a patch is applied.