CVE-2025-62759 is a Stored Cross-Site Scripting (XSS) vulnerability classified under CWE-79, found in the Justin Tadlock Series plugin for WordPress, affecting versions up to 2.0.1. The vulnerability stems from improper neutralization of user-supplied input during web page generation, allowing malicious scripts to be stored and later executed in the browsers of other users who view the affected content. This type of vulnerability can be exploited by an attacker with at least limited privileges (PR:L) who can inject crafted input that is not properly sanitized or encoded before being rendered. The CVSS 3.1 vector indicates network attack vector (AV:N), low attack complexity (AC:L), requiring privileges (PR:L), user interaction (UI:R), and a scope change (S:C), with impacts on confidentiality, integrity, and availability rated as low to medium. The scope change means the vulnerability affects components beyond the initially vulnerable component, increasing risk. Although no known exploits are currently reported in the wild, the potential for session hijacking, defacement, or data theft exists if exploited. The plugin is commonly used in WordPress environments for managing series or grouped content, making websites using this plugin susceptible to persistent XSS attacks. The vulnerability was reserved on 2025-10-21 and published on 2025-12-31, but no patch links are currently available, indicating that remediation may still be pending or in progress.

For European organizations, this vulnerability poses a risk primarily to websites using the Justin Tadlock Series plugin within WordPress environments. Exploitation could lead to unauthorized script execution in users' browsers, enabling session hijacking, credential theft, or unauthorized actions performed on behalf of legitimate users. This can compromise user data confidentiality and integrity, damage organizational reputation, and potentially disrupt service availability through defacement or malicious payloads. Given the widespread use of WordPress across Europe, especially in sectors like e-commerce, media, and public services, the impact could be significant if exploited at scale. The requirement for limited privileges and user interaction reduces the likelihood of mass exploitation but does not eliminate targeted attacks against high-value targets. Additionally, the scope change in the vulnerability increases the risk of broader impact beyond the immediate plugin context, potentially affecting other integrated components or user roles.

1. Monitor official sources and the vendor for patches or updates addressing CVE-2025-62759 and apply them promptly once available. 2. Implement strict input validation and output encoding on all user-supplied data within the Series plugin context to prevent malicious script injection. 3. Restrict user privileges to the minimum necessary, especially limiting who can submit or edit content that could be rendered by the plugin. 4. Employ Content Security Policy (CSP) headers to reduce the impact of potential XSS by restricting script execution sources. 5. Conduct regular security audits and code reviews focusing on input handling in custom or third-party plugins. 6. Use Web Application Firewalls (WAFs) with rules tuned to detect and block XSS payloads targeting the Series plugin. 7. Educate site administrators and users about the risks of clicking on suspicious links or interacting with untrusted content. 8. Monitor logs and user activity for signs of exploitation attempts or unusual behavior related to the plugin.