CVE-2025-9981 is a Stored Cross-Site Scripting (XSS) vulnerability classified under CWE-79, found in OpenSolution's QuickCMS product, specifically version 6.8. The vulnerability resides in the slider editor functionality (sliders-form), where an attacker with administrative privileges can inject arbitrary HTML and JavaScript code into the website content. This malicious code is then stored and rendered on every page, potentially affecting all visitors and users of the site. While the default admin user interface restricts direct JavaScript insertion, the vulnerability allows bypassing these restrictions under certain conditions, enabling script injection. The vendor was notified early but has not disclosed detailed vulnerability information or released patches, and other versions beyond 6.8 have not been tested but might also be vulnerable. The CVSS 4.0 score of 4.8 reflects a medium severity, considering the attack vector is network-based, requires high privileges (admin), and some user interaction, but does not impact confidentiality, integrity, or availability directly. No known exploits are currently reported in the wild. This vulnerability could be leveraged for persistent XSS attacks, leading to session hijacking, defacement, or distribution of malware through the affected CMS websites.

For European organizations using QuickCMS version 6.8, this vulnerability poses a risk of persistent XSS attacks that can compromise website visitors and internal users. Attackers with admin access could inject malicious scripts that execute in the context of the website, potentially stealing session tokens, redirecting users to malicious sites, or defacing web content. This could damage organizational reputation, lead to data breaches, and violate data protection regulations such as GDPR if personal data is compromised. Since the vulnerability requires admin privileges, the primary risk is insider threats or compromised admin accounts. The lack of vendor response and patches increases the risk exposure duration. Organizations running QuickCMS on public-facing websites, especially those handling sensitive user data or critical services, are at higher risk. The impact on availability and integrity is limited but the confidentiality of user sessions and data could be affected.

1. Restrict administrative access to QuickCMS to trusted personnel only and enforce strong authentication mechanisms, including multi-factor authentication (MFA). 2. Conduct a thorough review of all slider editor content for injected or suspicious scripts and remove any unauthorized code. 3. Implement Content Security Policy (CSP) headers to restrict the execution of inline scripts and reduce the impact of XSS attacks. 4. Monitor web server logs and CMS activity for unusual admin actions or content changes. 5. If possible, upgrade to a newer, patched version of QuickCMS once available or consider alternative CMS solutions with active security support. 6. Employ web application firewalls (WAF) with rules to detect and block XSS payloads targeting the slider editor endpoints. 7. Educate administrators about the risks of XSS and safe content management practices. 8. Regularly back up website content to enable quick restoration in case of defacement or compromise.