CVE-2025-10180 identifies a stored Cross-Site Scripting (XSS) vulnerability in the jhoppe Markdown Shortcode plugin for WordPress, present in all versions up to and including 0.2.1. The vulnerability arises from improper neutralization of user input (CWE-79) during web page generation, specifically due to insufficient sanitization and output escaping of user-supplied attributes in the 'markdown' shortcode. Authenticated attackers with contributor-level access or higher can exploit this flaw by injecting arbitrary JavaScript code into pages or posts via the shortcode attributes. When any user, including administrators or visitors, accesses the compromised page, the injected script executes in their browser context. This can lead to session hijacking, privilege escalation, or unauthorized actions performed on behalf of the victim. The vulnerability has a CVSS v3.1 base score of 6.4, reflecting a medium severity level, with an attack vector of network, low attack complexity, and requiring privileges but no user interaction. The scope is changed, indicating that the vulnerability can affect resources beyond the initially compromised component. No public exploits have been reported yet, but the presence of authenticated access requirements limits the attack surface to users with contributor or higher roles. The plugin is widely used in WordPress environments that enable markdown content via shortcodes, making it a relevant threat to many websites relying on this functionality.

For European organizations, this vulnerability poses a significant risk to the confidentiality and integrity of web applications running WordPress with the affected plugin. Attackers with contributor-level access—often granted to content creators or editors—can inject malicious scripts that execute in the browsers of site visitors and administrators, potentially leading to session hijacking, theft of sensitive data, or unauthorized administrative actions. This can result in data breaches, defacement, or further compromise of internal systems if administrative credentials are stolen. The impact is particularly concerning for organizations with collaborative content management workflows involving multiple contributors. Additionally, compromised websites can damage organizational reputation and trust, especially in sectors with strict data protection regulations like GDPR. Although availability is not directly impacted, the indirect consequences of exploitation can disrupt business operations and require costly incident response efforts.

European organizations should take immediate action to mitigate this vulnerability by: 1) Identifying and inventorying all WordPress sites using the jhoppe Markdown Shortcode plugin and verifying the installed version. 2) Removing or disabling the vulnerable plugin if no update or patch is available, or applying vendor-provided patches as soon as they are released. 3) Restricting contributor-level access to trusted users only and reviewing user roles and permissions to minimize the number of users who can exploit this vulnerability. 4) Implementing additional input validation and output escaping controls at the application or web server level to prevent injection of malicious scripts. 5) Monitoring web server and application logs for unusual activity indicative of exploitation attempts. 6) Educating content contributors about the risks of injecting untrusted content and enforcing secure content creation policies. 7) Employing Content Security Policy (CSP) headers to limit the impact of any injected scripts. 8) Regularly scanning WordPress environments with security tools to detect vulnerabilities and malicious code injections.