CVE-2025-9647 is a cross-site scripting (XSS) vulnerability identified in the mtons mblog software, affecting versions up to and including 3.5.0. The vulnerability arises from improper handling of the 'Name' argument in the /admin/role/list endpoint. Specifically, the application fails to adequately sanitize or encode user-supplied input for this parameter, allowing an attacker to inject malicious scripts. This vulnerability is exploitable remotely without requiring authentication, although it does require user interaction (e.g., a victim clicking a crafted link or visiting a malicious page). The CVSS 4.0 base score is 5.3, indicating a medium severity level. The attack vector is network-based (AV:N), with low attack complexity (AC:L), no privileges required (PR:N), and no user authentication needed (AT:N). The impact primarily affects the integrity of the victim's browsing session (VI:L), with no direct impact on confidentiality or availability. The vulnerability does not involve scope changes or security requirements. Although no public exploit is currently known to be actively used in the wild, proof-of-concept exploits have been made publicly available, increasing the risk of exploitation. XSS vulnerabilities like this can be leveraged for session hijacking, defacement, phishing, or delivering malware payloads, especially targeting administrative users given the affected endpoint is under /admin. This elevates the risk of privilege escalation or unauthorized administrative actions if exploited successfully.

For European organizations using mtons mblog versions 3.0 through 3.5.0, this vulnerability poses a moderate risk. Since the affected endpoint is administrative, exploitation could lead to compromise of administrative sessions, enabling attackers to perform unauthorized actions, manipulate roles, or escalate privileges within the blogging platform. This could result in defacement, data manipulation, or use of the platform as a pivot point for further attacks. The impact on confidentiality is limited but not negligible, as session tokens or sensitive administrative data could be exposed. Integrity is moderately impacted due to potential unauthorized changes. Availability is not directly affected. Organizations in sectors with high reliance on web content management, such as media, education, or government, may face reputational damage and operational disruption if exploited. The medium CVSS score reflects the balance between ease of exploitation and limited impact scope. However, the public availability of exploits increases the urgency for mitigation. European organizations must consider the risk of targeted phishing campaigns leveraging this vulnerability to compromise administrative users.

1. Immediate upgrade to a patched version of mtons mblog once available; if no patch is currently released, apply any vendor-provided workarounds or temporary mitigations. 2. Implement strict input validation and output encoding on the 'Name' parameter in /admin/role/list to neutralize malicious scripts. 3. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in the browser. 4. Restrict access to the /admin interface via network-level controls such as VPNs, IP whitelisting, or web application firewalls (WAFs) with rules to detect and block XSS payloads. 5. Educate administrative users about phishing risks and encourage cautious behavior when clicking on links, especially those that appear suspicious. 6. Monitor web server and application logs for unusual requests targeting the vulnerable endpoint, and set up alerts for potential exploitation attempts. 7. Conduct regular security assessments and penetration testing focused on web application vulnerabilities, including XSS. 8. Consider implementing multi-factor authentication (MFA) for administrative accounts to reduce the impact of session hijacking.