CVE-2025-9981 is a stored Cross-Site Scripting (XSS) vulnerability classified under CWE-79 affecting OpenSolution QuickCMS version 6.8. The vulnerability exists 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 injected code is then rendered and executed on every page load, potentially allowing the attacker to perform actions such as session hijacking, defacement, or delivering malicious payloads to site visitors. Although the default configuration restricts admin users from adding JavaScript, this vulnerability bypasses that limitation, enabling script injection. The vendor was notified early but has not disclosed detailed vulnerability information or provided patches; only version 6.8 has been confirmed vulnerable, while other versions remain untested and possibly affected. The CVSS v4.0 base score is 4.8 (medium severity), reflecting that the attack vector is network-based, requires low attack complexity, no user interaction, but does require high privileges (admin rights). The vulnerability does not affect confidentiality, integrity, or availability directly but poses a risk to website integrity and user trust. No known exploits are currently reported in the wild, but the potential for abuse exists given the nature of stored XSS. The vulnerability is publicly disclosed and assigned by CERT-PL.

For European organizations, this vulnerability poses a risk primarily to the integrity and trustworthiness of their web presence. Organizations using QuickCMS 6.8 to manage public-facing websites could have malicious scripts injected that execute in the browsers of site visitors, potentially leading to session hijacking, credential theft, or distribution of malware. This could damage brand reputation, lead to regulatory scrutiny under GDPR if personal data is compromised, and cause operational disruptions if the website is defaced or manipulated. Since exploitation requires administrative privileges, the impact is mitigated somewhat by the need to protect admin accounts; however, insider threats or compromised admin credentials could enable exploitation. The lack of vendor patches increases risk exposure. European entities in sectors with high public interaction such as government, education, media, and e-commerce are particularly vulnerable. The vulnerability does not directly impact availability or confidentiality of backend systems but can lead to indirect impacts through trust erosion and potential data leakage via client-side attacks.

1. Immediately restrict and audit administrative access to QuickCMS, enforcing strong authentication mechanisms such as multi-factor authentication (MFA) to reduce the risk of credential compromise. 2. Review and sanitize all slider content inputs manually or via custom scripts to detect and remove any injected HTML or JavaScript code until an official patch is available. 3. Implement Content Security Policy (CSP) headers to limit the execution of unauthorized scripts on the website, reducing the impact of injected scripts. 4. Monitor website content and logs for unusual changes or suspicious activity related to the slider editor functionality. 5. Isolate the CMS administration interface from public networks where possible, restricting access via VPN or IP whitelisting. 6. Engage with the vendor for updates and patches, and plan for timely application once released. 7. Consider migrating to a different CMS or version if no patch is forthcoming and the risk is unacceptable. 8. Educate administrators on the risks of stored XSS and safe content management practices. 9. Use web application firewalls (WAF) with custom rules to detect and block attempts to inject malicious scripts via the slider editor.