CVE-2025-41062 is a medium-severity vulnerability identified in version 4.0.5 of the appRain CMF (Content Management Framework). The vulnerability is classified as CWE-79, which corresponds to improper neutralization of input during web page generation, commonly known as Cross-site Scripting (XSS). Specifically, this is an authenticated reflected XSS vulnerability that arises due to insufficient validation and sanitization of user-supplied input in the 'page' parameter within the /apprain/developer/addons endpoint. Because the vulnerability requires authentication, an attacker must have valid credentials to exploit it. The vulnerability allows an attacker to inject malicious scripts that are reflected back to the user, potentially leading to session hijacking, credential theft, or execution of arbitrary JavaScript in the context of the victim's browser. The CVSS 4.0 base score is 4.8, indicating a medium severity level. The attack vector is network-based with low attack complexity and no privileges required beyond authentication. User interaction is required for the malicious payload to execute, and the vulnerability has a limited scope affecting confidentiality and integrity but not availability. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was reserved in April 2025 and published in September 2025, with INCIBE as the assigner. Given the nature of the vulnerability, it primarily targets authenticated users of the appRain CMF platform, which is used for web content management and development.

For European organizations using appRain CMF version 4.0.5, this vulnerability poses a risk of client-side script injection that could compromise user sessions and data confidentiality. Attackers exploiting this flaw could execute malicious scripts in the context of authenticated users, potentially leading to unauthorized actions, theft of sensitive information, or further pivoting within the affected environment. Although the vulnerability requires authentication, it could be leveraged by insiders or attackers who have obtained credentials through phishing or other means. This could impact organizations that rely on appRain CMF for managing web content, including government agencies, educational institutions, and private enterprises. The impact is particularly relevant for organizations handling sensitive or regulated data under GDPR, as exploitation could lead to data breaches and regulatory non-compliance. Additionally, the reflected XSS could be used as a vector for social engineering attacks targeting employees or customers. The absence of known exploits reduces immediate risk, but the medium severity and ease of exploitation mean organizations should act promptly to mitigate exposure.

To mitigate this vulnerability, European organizations should first verify if they are running appRain CMF version 4.0.5 and restrict access to the /apprain/developer/addons endpoint to trusted users only. Since no official patch is currently available, organizations should implement input validation and output encoding controls at the application or web server level to sanitize the 'page' parameter. Web Application Firewalls (WAFs) can be configured with custom rules to detect and block malicious payloads targeting this parameter. Additionally, enforcing strong authentication mechanisms and monitoring user activities for anomalous behavior can reduce the risk of credential compromise and exploitation. Organizations should also educate users about the risks of phishing and credential theft to prevent attackers from gaining authenticated access. Regular security assessments and penetration testing focused on XSS vulnerabilities in the appRain CMF environment are recommended. Once a vendor patch is released, prompt application of the update is critical. Finally, implementing Content Security Policy (CSP) headers can help mitigate the impact of XSS by restricting the execution of unauthorized scripts in browsers.