CVE-2025-2537 is a medium-severity stored Cross-Site Scripting (XSS) vulnerability affecting the WordPress plugin 'YouTube Embed, Playlist and Popup' developed by WpDevArt. The vulnerability arises from improper neutralization of input during web page generation, specifically due to insufficient input sanitization and output escaping in the plugin's bundled ThickBox JavaScript library (version 3.1). This flaw allows authenticated attackers with contributor-level or higher privileges to inject arbitrary malicious scripts into pages managed by the plugin. When other users access these compromised pages, the injected scripts execute in their browsers, potentially leading to session hijacking, privilege escalation, or unauthorized actions performed on behalf of the victim. The vulnerability does not require user interaction beyond visiting the injected page, and it affects all versions of the plugin. The CVSS 3.1 base score is 6.4, reflecting a medium severity with network attack vector, low attack complexity, and privileges required. The scope is changed (S:C), indicating that the vulnerability can affect resources beyond the initially vulnerable component. No public exploits are known at this time, and no patches have been linked yet. The vulnerability is categorized under CWE-79, which is a common and well-understood web application security weakness involving improper input validation leading to XSS attacks.

For European organizations using WordPress sites with the vulnerable WpDevArt YouTube Embed, Playlist and Popup plugin, this vulnerability poses a significant risk to the confidentiality and integrity of user sessions and data. Attackers with contributor-level access can inject malicious scripts that execute in the context of other users, including administrators or site visitors, potentially leading to theft of authentication cookies, defacement, or unauthorized actions such as content manipulation or privilege escalation. This can undermine trust in the affected websites, lead to data breaches, and cause reputational damage. Given the widespread use of WordPress in Europe for business, government, and non-profit websites, the vulnerability could be exploited to target sensitive information or disrupt services. The lack of requirement for user interaction beyond page access increases the risk of automated or widespread exploitation once an attacker gains contributor access. However, the need for authenticated contributor-level privileges limits the attack surface to insiders or compromised accounts, reducing the likelihood of opportunistic external attacks but increasing the risk from insider threats or credential theft.

European organizations should immediately audit their WordPress installations to identify the presence of the WpDevArt YouTube Embed, Playlist and Popup plugin. Until an official patch is released, administrators should consider disabling or removing the plugin to eliminate the attack vector. Access controls should be tightened to restrict contributor-level privileges only to trusted users, and multi-factor authentication (MFA) should be enforced to reduce the risk of account compromise. Web application firewalls (WAFs) can be configured to detect and block suspicious script injection patterns associated with this vulnerability. Additionally, organizations should monitor logs for unusual contributor activity and conduct regular security reviews of user-generated content. Once a patch becomes available, it should be applied promptly. Developers and site administrators should also consider implementing Content Security Policy (CSP) headers to limit the execution of unauthorized scripts and employ security plugins that sanitize user inputs and outputs more robustly.