CVE-2025-14000 is a stored Cross-Site Scripting (XSS) vulnerability identified in the Membership Plugin – Restrict Content developed by stellarwp for WordPress. The flaw exists in all versions up to and including 3.2.15 and arises from improper neutralization of user-supplied input in the plugin’s 'register_form' and 'restrict' shortcodes. Specifically, the plugin fails to adequately sanitize and escape attributes provided by authenticated users with contributor-level access or higher. This deficiency allows these users to inject arbitrary JavaScript code into pages generated by the plugin. When other users visit these pages, the injected scripts execute in their browsers, potentially enabling session hijacking, privilege escalation, defacement, or the delivery of further malicious payloads. The vulnerability is classified under CWE-79, indicating improper input neutralization during web page generation. The CVSS v3.1 base score is 6.4, reflecting a medium severity level, with an attack vector of network, low attack complexity, requiring privileges (contributor or above), no user interaction, and a scope change due to affecting other users. No public exploits have been reported yet, but the vulnerability poses a risk to WordPress sites using this plugin, especially those with multiple contributors. The vulnerability’s impact is primarily on confidentiality and integrity, as attackers can execute scripts in the context of other users. The plugin’s widespread use in membership and content restriction scenarios makes this a significant concern for organizations relying on WordPress for content management and user interaction.

For European organizations, this vulnerability can lead to unauthorized script execution within trusted websites, compromising user sessions and potentially exposing sensitive information such as authentication tokens or personal data. Since the attack requires contributor-level access, insider threats or compromised contributor accounts pose a significant risk. Exploitation could facilitate lateral movement within the organization’s web infrastructure or enable phishing attacks by altering site content. The integrity of web content can be undermined, damaging organizational reputation and trust. Although availability is not directly impacted, the resulting security incidents could lead to downtime or remediation costs. Organizations in sectors with strict data protection regulations, such as finance, healthcare, and e-commerce, face heightened compliance risks if user data is exposed. The vulnerability’s presence in membership and content restriction plugins increases the likelihood of targeting sites with user-generated content or subscription models, common in European digital services.

Organizations should immediately audit their WordPress installations to identify the use of the Membership Plugin – Restrict Content and verify the plugin version. Until an official patch is released, restrict contributor-level permissions to trusted users only and consider temporarily disabling the plugin or the affected shortcodes if feasible. Implement additional server-side input validation and output encoding to neutralize potentially malicious inputs. Employ Web Application Firewalls (WAFs) with custom rules to detect and block suspicious shortcode attribute payloads. Monitor logs for unusual contributor activity and conduct regular security awareness training to reduce insider risks. Once a patch is available, apply it promptly and test the update in a staging environment before production deployment. Additionally, enforce least privilege principles for user roles and consider multi-factor authentication to reduce the risk of compromised contributor accounts. Regularly review and update security policies related to plugin management and user access controls.