CVE-2025-62899 is a Stored Cross-Site Scripting (XSS) vulnerability identified in the Photospace Responsive theme developed by THRIVE - Web Design Gold Coast, affecting versions up to and including 2.2.0. The vulnerability stems from improper neutralization of user-supplied input during the generation of web pages, allowing attackers to inject malicious scripts that are stored persistently on the server and executed in the context of other users' browsers when they view the affected pages. The CVSS 3.1 base score is 5.4 (medium), with an attack vector of network (remote), low attack complexity, requiring privileges (PR:L), and user interaction (UI:R). The scope is changed (S:C), indicating that exploitation can affect resources beyond the vulnerable component. The impact affects confidentiality and integrity partially, with no impact on availability. Exploitation requires an authenticated user to submit crafted input that is not properly sanitized or encoded before being rendered, enabling script execution in other users' sessions. This can lead to session hijacking, theft of sensitive data, or unauthorized actions performed on behalf of victims. No patches or known exploits are currently publicly available, but the vulnerability is published and should be addressed promptly. The vulnerability is relevant to organizations using the Photospace Responsive theme in their web presence, especially those relying on WordPress-based sites where this theme is deployed. The improper input handling indicates a failure in secure coding practices related to output encoding and input validation, which are critical for preventing XSS attacks.

For European organizations, this vulnerability poses a risk primarily to web applications using the Photospace Responsive theme, potentially exposing users to session hijacking, credential theft, and unauthorized actions. Confidentiality and integrity of user data can be compromised, leading to reputational damage and potential regulatory consequences under GDPR if personal data is exposed. Although availability is not impacted, the trustworthiness of affected web services can be undermined. Attackers with limited privileges can exploit this vulnerability by tricking authenticated users into interacting with malicious content, increasing the risk of targeted attacks such as spear phishing or social engineering. Organizations in sectors with high web presence, including e-commerce, media, and public services, may face increased risk. The lack of known exploits reduces immediate threat but does not eliminate the risk, especially as attackers often weaponize such vulnerabilities once disclosed. The vulnerability could also be leveraged as a foothold for further attacks within the network if combined with other weaknesses.

1. Monitor for and apply official patches or updates from THRIVE - Web Design Gold Coast as soon as they become available for Photospace Responsive theme versions up to 2.2.0. 2. Implement strict input validation on all user-supplied data, ensuring that inputs are sanitized to remove or encode potentially malicious characters before storage. 3. Employ context-aware output encoding (e.g., HTML entity encoding) when rendering user input in web pages to prevent script execution. 4. Restrict user privileges to the minimum necessary, limiting the ability of users to submit content that can be stored and rendered. 5. Use Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 6. Conduct regular security audits and penetration testing focusing on input handling and XSS vulnerabilities. 7. Educate users and administrators about the risks of XSS and safe browsing practices to reduce successful exploitation via social engineering. 8. Consider deploying Web Application Firewalls (WAFs) with rules to detect and block common XSS attack patterns targeting the affected theme. 9. Review and harden the configuration of the WordPress environment and plugins to minimize attack surface.