CVE-2025-41036 is a stored Cross-Site Scripting (XSS) vulnerability identified in appRain CMF version 4.0.5, a content management framework used for building web applications. The vulnerability arises from improper neutralization of input during web page generation, specifically in the parameters 'data[Admin][description]', 'data[Admin][f_name]', and 'data[Admin][l_name]' within the administrative account editing interface (/apprain/admin/account/edit). Because these inputs 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 view the affected pages. This stored XSS can lead to session hijacking, credential theft, defacement, or further exploitation of the affected system. The CVSS 4.0 base score is 5.1 (medium severity), reflecting that the vulnerability can be exploited remotely without authentication (AV:N), with low attack complexity (AC:L), but requires some privileges (PR:L) and user interaction (UI:P). The vulnerability does not impact confidentiality, integrity, or availability directly (VC:N/VI:N/VA:N), but it does have limited scope (S:L) and impact (SI:L). No known exploits are currently reported in the wild, and no official patches have been released yet. The vulnerability was assigned by INCIBE and publicly disclosed on September 4, 2025.

For European organizations using appRain CMF 4.0.5, this vulnerability poses a moderate risk. Stored XSS can allow attackers to execute arbitrary JavaScript in the context of the victim's browser, potentially leading to theft of session cookies, user impersonation, or distribution of malware. Since the vulnerability requires authenticated access with low privileges, internal threat actors or compromised accounts could exploit it to escalate attacks. This can undermine trust in web applications, lead to data leakage, and facilitate further attacks such as phishing or lateral movement within networks. Organizations handling sensitive personal data under GDPR must be cautious, as exploitation could result in data breaches and regulatory penalties. The absence of known exploits reduces immediate risk, but the medium CVSS score and the nature of stored XSS warrant timely remediation to prevent exploitation, especially in sectors like finance, healthcare, and government where web application integrity is critical.

1. Immediate mitigation should include restricting access to the administrative account editing interface to trusted personnel only and monitoring logs for suspicious activity. 2. Implement strict input validation and output encoding on the affected parameters ('data[Admin][description]', 'data[Admin][f_name]', 'data[Admin][l_name]') to neutralize malicious scripts. 3. Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in browsers. 4. Conduct a thorough code review of the appRain CMF source to identify and remediate similar input handling issues elsewhere. 5. If possible, upgrade to a patched version once available or apply vendor-provided patches promptly. 6. Educate administrators about the risks of XSS and enforce strong authentication and session management controls to reduce the risk of account compromise. 7. Use web application firewalls (WAFs) with custom rules to detect and block XSS payloads targeting these parameters. 8. Regularly scan the web application with automated tools to detect XSS and other injection flaws.