CVE-2025-6061 is a stored Cross-Site Scripting (XSS) vulnerability affecting the 'kk Youtube Video' WordPress plugin developed by bhittani. This vulnerability exists in all versions up to and including 0.2 of the plugin. The root cause is insufficient input sanitization and output escaping on user-supplied attributes within the plugin's 'kkytv' shortcode. Authenticated users with contributor-level privileges or higher can exploit this flaw by injecting arbitrary JavaScript code into pages or posts that utilize this shortcode. When other users access these compromised pages, the malicious scripts execute in their browsers, potentially leading to session hijacking, privilege escalation, or redirection to malicious sites. The vulnerability does not require user interaction beyond visiting the infected page, and no higher privileges than contributor are needed to inject the payload. The CVSS v3.1 score is 6.4 (medium severity), reflecting network attack vector, low attack complexity, privileges required (low), no user interaction, and a scope change with limited confidentiality and integrity impact but no availability impact. No known exploits are currently reported in the wild, and no patches have been published yet. The vulnerability is categorized under CWE-79, which is a common and well-understood web application security issue related to improper neutralization of input during web page generation.

For European organizations, this vulnerability poses a moderate risk primarily to websites running WordPress with the vulnerable 'kk Youtube Video' plugin installed. The impact includes potential theft of user credentials, session tokens, or other sensitive information through malicious script execution. This can lead to unauthorized access, data leakage, or further compromise of the website and its users. Given that contributor-level access is sufficient to exploit the vulnerability, insider threats or compromised contributor accounts could be leveraged by attackers. The scope of impact extends to any users visiting the infected pages, including customers, employees, or partners, potentially damaging organizational reputation and trust. While the vulnerability does not directly affect availability, the integrity and confidentiality of web content and user data are at risk. European organizations with public-facing WordPress sites that use this plugin, especially those in sectors with high web presence such as media, e-commerce, and education, are more vulnerable. Additionally, regulatory frameworks like GDPR impose strict requirements on protecting personal data, and exploitation of this vulnerability could lead to compliance issues and financial penalties.

1. Immediate mitigation involves restricting contributor-level users from adding or editing content that includes the 'kkytv' shortcode until a patch is available. 2. Implement a Web Application Firewall (WAF) with custom rules to detect and block suspicious script injections related to the shortcode parameters. 3. Conduct a thorough audit of all WordPress sites to identify installations of the 'kk Youtube Video' plugin and assess usage of the vulnerable shortcode. 4. Educate content contributors about the risks of inserting untrusted inputs and enforce strict content review processes before publishing. 5. Monitor website logs and user activity for signs of unusual script injections or unauthorized content modifications. 6. Once a patch is released by the vendor, prioritize immediate update of the plugin. 7. As a longer-term measure, consider replacing the vulnerable plugin with a more secure alternative or custom-developed solution that follows secure coding practices for input validation and output encoding. 8. Employ Content Security Policy (CSP) headers to restrict execution of unauthorized scripts on affected sites, reducing the impact of potential XSS payloads.