CVE-2025-41041 is a stored Cross-Site Scripting (XSS) vulnerability identified in version 4.0.5 of the appRain CMF (Content Management Framework). The vulnerability arises from improper neutralization of user-supplied input during web page generation, specifically within the parameters 'data[code]', 'data[lang][0][key]', 'data[lang][0][value]', 'data[lang][1][key]', and 'data[title]' in the /apprain/developer/language/default.xml endpoint. Because these inputs are not properly validated or sanitized, an authenticated attacker can inject malicious scripts that are stored persistently on the server and executed in the browsers of users who access the affected pages. This stored XSS can lead to session hijacking, defacement, or redirection to malicious sites. The vulnerability requires low privileges (authenticated user) and some user interaction (victim visiting the malicious content). The CVSS 4.0 base score is 5.1 (medium severity), reflecting network attack vector, low attack complexity, no privileges required beyond authentication, and limited scope impact. No known exploits are reported in the wild yet. The vulnerability is classified under CWE-79, which covers improper neutralization of input leading to XSS attacks. The lack of a patch link indicates that a fix might not yet be publicly available or announced. Organizations using appRain CMF 4.0.5 should consider this vulnerability a moderate risk, especially if the affected parameters are exposed to authenticated users who can submit content that is then rendered to others.

For European organizations using appRain CMF 4.0.5, this vulnerability poses a moderate risk to confidentiality and integrity of user sessions and data. Stored XSS can allow attackers to steal session cookies, perform actions on behalf of users, or deliver malware. This can lead to unauthorized access, data leakage, or reputational damage. The impact is particularly significant for organizations with sensitive user data or those that rely on appRain CMF for public-facing web applications. Since the vulnerability requires authentication, internal users or contributors with legitimate access could exploit it, increasing insider threat risks. The availability impact is minimal, as XSS typically does not cause denial of service. However, successful exploitation could undermine user trust and compliance with data protection regulations such as GDPR, especially if personal data is compromised. European organizations should be vigilant in monitoring for suspicious activity and consider the risk in their threat models.

1. Immediate mitigation includes restricting access to the affected /apprain/developer/language/default.xml endpoint to trusted administrators only, minimizing the number of users who can submit data to the vulnerable parameters. 2. Implement strict input validation and output encoding on the server side for the parameters 'data[code]', 'data[lang][0][key]', 'data[lang][0][value]', 'data[lang][1][key]', and 'data[title]'. Use context-aware encoding (e.g., HTML entity encoding) to neutralize any injected scripts. 3. Employ Content Security Policy (CSP) headers to reduce the impact of potential XSS by restricting script sources and disabling inline scripts. 4. Monitor logs for unusual input patterns or repeated attempts to inject scripts, especially from authenticated users. 5. Educate users and administrators about the risks of XSS and encourage reporting of suspicious behavior. 6. Stay updated with appRain vendor advisories for patches or official fixes and apply them promptly once available. 7. Consider deploying Web Application Firewalls (WAFs) with rules to detect and block common XSS payloads targeting these parameters. 8. Conduct regular security assessments and penetration testing focusing on input validation and XSS vulnerabilities in appRain CMF deployments.