CVE-2025-11289 is a cross-site scripting vulnerability identified in the westboy CicadasCMS product, specifically affecting versions up to commit 2431154dac8d0735e04f1fd2a3c3556668fc8dab. The vulnerability resides in the Save function of the Template Management Page, implemented in the TemplateFileServiceImpl.java file. This function fails to properly sanitize user input before processing template files, allowing an attacker to inject malicious JavaScript code. The vulnerability can be triggered remotely without authentication, but requires user interaction, such as an administrator or editor saving a crafted template. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:H means high privileges required, but the vector states PR:H which is contradictory; assuming PR:H means privileges required), user interaction required (UI:P), and limited impact on confidentiality (C:N), integrity (I:L), and no impact on availability (A:N). The exploit could lead to session hijacking, credential theft, or unauthorized actions performed in the context of the victim's browser session. Although no known exploits are currently active in the wild, the public disclosure increases the risk of exploitation. The lack of a patch link suggests that a fix may not yet be available, emphasizing the need for immediate mitigation steps.

For European organizations, this XSS vulnerability poses a risk primarily to the confidentiality and integrity of web sessions managed via CicadasCMS. Successful exploitation could allow attackers to execute arbitrary scripts in the context of administrative users, potentially leading to credential theft, session hijacking, or unauthorized content manipulation. This could result in defacement, data leakage, or further compromise of internal systems. Organizations with public-facing CMS management portals are particularly vulnerable. The medium severity rating reflects that while the vulnerability is exploitable remotely, it requires user interaction and privileges, limiting the attack surface. However, given the public disclosure and potential for targeted attacks, the threat should not be underestimated. The impact is heightened for sectors relying heavily on web content management for critical communications or e-commerce, including government, media, and financial institutions across Europe.

1. Monitor for official patches or updates from westboy and apply them promptly once released. 2. Implement strict input validation and output encoding on all template management inputs to prevent injection of malicious scripts. 3. Employ Web Application Firewalls (WAFs) configured to detect and block common XSS payloads targeting the affected CMS components. 4. Restrict access to the Template Management Page to trusted users and networks, using VPNs or IP whitelisting where possible. 5. Conduct regular security audits and penetration testing focusing on CMS components to identify and remediate similar vulnerabilities. 6. Educate administrators and editors about the risks of interacting with untrusted content or links that could trigger XSS attacks. 7. Implement Content Security Policy (CSP) headers to reduce the impact of potential XSS exploitation by restricting script execution sources. 8. Monitor logs for suspicious activities related to template saving operations to detect potential exploitation attempts early.