CVE-2025-12650 is a stored Cross-Site Scripting (XSS) vulnerability identified in the Simple post listing plugin for WordPress, developed by sgcoskey. The vulnerability exists in all versions up to and including 0.2 due to insufficient sanitization and escaping of the 'class_name' parameter within the postlist shortcode. This parameter accepts user-supplied input that is embedded into web pages without proper neutralization, allowing an authenticated attacker with contributor-level permissions or higher to inject arbitrary JavaScript code. Because the injected scripts are stored persistently, they execute whenever any user accesses the compromised page and interacts with it via mouse actions. The vulnerability is classified under CWE-79, indicating improper neutralization of input during web page generation. The CVSS 3.1 base score is 6.4, reflecting a medium severity with network attack vector, low attack complexity, privileges required (low), no user interaction needed, and a scope change. The impact primarily affects confidentiality and integrity, as malicious scripts can steal session tokens, perform actions on behalf of users, or alter page content. No patches or official fixes are currently linked, and no known exploits have been reported in the wild. The vulnerability highlights a common security weakness in WordPress plugins where insufficient input validation leads to stored XSS, a frequent vector for web application attacks.

For European organizations, the impact of CVE-2025-12650 can be significant, especially for those relying on WordPress sites with the Simple post listing plugin installed. Exploitation allows attackers with contributor-level access to inject persistent malicious scripts that execute in the browsers of site visitors or administrators. This can lead to session hijacking, unauthorized actions performed with victim credentials, defacement, or distribution of malware. Confidential information such as authentication tokens or personal data could be exposed, violating GDPR requirements and potentially resulting in regulatory penalties. The integrity of website content and user trust may be compromised, damaging brand reputation. Since the attack requires authenticated access, insider threats or compromised contributor accounts are primary vectors. The vulnerability can also be leveraged as a foothold for further attacks within an organization’s web infrastructure. Given the widespread use of WordPress in Europe, especially among SMEs and public sector entities, the risk is non-trivial. The lack of a patch increases exposure time, and organizations with limited security monitoring may remain unaware of exploitation attempts.

To mitigate CVE-2025-12650, organizations should first verify if the Simple post listing plugin (sgcoskey) is installed and identify the version in use. Immediate steps include: 1) Restrict contributor-level permissions strictly to trusted users and audit existing user roles to minimize risk of malicious input. 2) Disable or remove the vulnerable plugin if it is not essential, or replace it with a secure alternative that properly sanitizes inputs. 3) Implement Web Application Firewall (WAF) rules to detect and block suspicious payloads targeting the 'class_name' parameter in postlist shortcodes. 4) Employ Content Security Policy (CSP) headers to limit script execution sources and reduce impact of injected scripts. 5) Monitor logs and user activity for unusual behavior indicative of exploitation attempts. 6) Educate content contributors on safe input practices and the risks of injecting untrusted content. 7) Follow vendor announcements for patches or updates and apply them promptly once available. 8) Conduct regular security assessments and penetration tests focused on WordPress plugins to identify similar vulnerabilities proactively.