CVE-2025-62137 is a stored Cross-site Scripting (XSS) vulnerability classified under CWE-79, affecting the Shuttle product by Shuttlethemes up to version 1.5.0. The vulnerability stems from improper neutralization of user-supplied input during web page generation, which allows attackers to inject malicious scripts that are stored persistently on the server and executed in the browsers of users who visit the affected pages. This type of vulnerability can be exploited remotely over the network (AV:N) with low attack complexity (AC:L), requiring the attacker to have some privileges (PR:L) and user interaction (UI:R). The vulnerability impacts confidentiality, integrity, and availability partially (C:L/I:L/A:L) and has a CVSS v3.1 base score of 6.5, indicating medium severity. Although no known exploits are currently reported in the wild, the stored nature of the XSS makes it particularly dangerous as it can affect multiple users and persist until remediated. The vulnerability could enable attackers to steal session cookies, perform actions on behalf of users, deface websites, or deliver malware. The lack of an official patch at the time of reporting necessitates interim mitigations such as input validation, output encoding, and Content Security Policy enforcement. Organizations using Shuttle themes for their web presence should audit their installations and prepare to deploy patches once available.

For European organizations, this vulnerability poses risks primarily to web applications using the Shuttle theme, potentially exposing users to session hijacking, credential theft, and unauthorized actions. This can lead to data breaches, reputational damage, and service disruption. Sectors with high web traffic and sensitive data, such as e-commerce, government portals, and financial services, are particularly vulnerable. The stored XSS nature means that once exploited, multiple users can be affected, amplifying the impact. Additionally, attackers could leverage this vulnerability to pivot into deeper network layers if combined with other weaknesses. The medium CVSS score reflects moderate but non-negligible risk, emphasizing the need for timely mitigation. Given the interconnected nature of European digital infrastructure, exploitation in one organization could have cascading effects, especially in critical infrastructure or public service websites.

1. Monitor Shuttlethemes official channels for patches addressing CVE-2025-62137 and apply them promptly upon release. 2. Implement strict input validation on all user-supplied data, ensuring that inputs are sanitized and disallowed characters or scripts are filtered out before storage or rendering. 3. Apply context-aware output encoding (e.g., HTML entity encoding) to neutralize any potentially malicious content before it is rendered in browsers. 4. Deploy a robust Content Security Policy (CSP) that restricts the execution of inline scripts and limits the sources of executable scripts to trusted domains. 5. Conduct regular security audits and penetration testing focusing on XSS vulnerabilities in web applications using Shuttle themes. 6. Educate developers and administrators on secure coding practices and the risks associated with stored XSS. 7. Use web application firewalls (WAFs) with rules tuned to detect and block XSS payloads targeting Shuttle-based applications. 8. Limit user privileges to the minimum necessary to reduce the risk of privilege escalation that facilitates exploitation.