CVE-2025-51488 is a Stored Cross-Site Scripting (XSS) vulnerability identified in MoonShine software versions prior to 3.12.4. This vulnerability allows remote attackers to inject and store arbitrary JavaScript code by submitting a malicious HTML payload within the 'Name' parameter during the creation of a new Admin user. Stored XSS vulnerabilities occur when untrusted input is saved by the application and later rendered in a web page without proper sanitization or encoding, enabling the execution of malicious scripts in the context of other users' browsers. In this case, the vulnerability is specifically triggered when an attacker crafts a payload in the Name field for a new Admin account, which is then stored and executed when viewed by administrators or other privileged users. The CVSS v3.1 base score is 4.9 (medium severity), with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), but requiring high privileges (PR:H) and no user interaction (UI:N). The impact is rated as high on confidentiality (C:H), but no impact on integrity (I:N) or availability (A:N). This suggests that the vulnerability could lead to unauthorized disclosure of sensitive information accessible to the admin user context, but does not allow modification or disruption of services. No known exploits are currently reported in the wild, and no patches are linked yet, indicating that mitigation may require upgrading to version 3.12.4 or applying vendor-provided fixes once available. The underlying weakness is classified under CWE-79, which covers improper neutralization of input leading to XSS.

For European organizations using MoonShine software, particularly those managing administrative interfaces exposed to multiple users, this vulnerability poses a risk of sensitive information disclosure. Since the attack requires high privileges to create a new Admin user, the threat is primarily from insider attackers or compromised privileged accounts. Successful exploitation could allow attackers to execute scripts in the context of admin users, potentially stealing session tokens, credentials, or other confidential data accessible in the admin interface. This could lead to further compromise of organizational systems or data breaches. Given the medium CVSS score and the requirement for high privileges, the risk is moderate but significant in environments with multiple administrators or where privilege escalation is possible. The lack of impact on integrity and availability reduces the risk of direct system manipulation or denial of service, but confidentiality breaches can still have serious regulatory and reputational consequences, especially under GDPR requirements in Europe.

European organizations should prioritize upgrading MoonShine to version 3.12.4 or later as soon as the patch becomes available to remediate this vulnerability. In the interim, organizations should enforce strict access controls and monitoring on administrative accounts to prevent unauthorized creation of new Admin users. Implementing multi-factor authentication (MFA) for all privileged accounts can reduce the risk of account compromise. Additionally, input validation and output encoding should be reviewed and enhanced in the application to prevent injection of malicious scripts. Web Application Firewalls (WAFs) can be configured to detect and block suspicious payloads targeting the Name parameter during admin creation. Regular security audits and penetration testing focused on privilege escalation and XSS vulnerabilities are recommended. Finally, educating administrators about the risks of stored XSS and encouraging cautious handling of user-generated content in admin interfaces can help mitigate exploitation.