CVE-2025-10638 identifies a missing authorization vulnerability (CWE-862) in the NS Maintenance Mode for WP WordPress plugin versions up to 1.3.1. Specifically, the subscriber export functionality does not enforce any authorization controls, allowing unauthenticated remote attackers to retrieve a list of site subscribers, including their names and email addresses. This vulnerability arises from the plugin's failure to verify whether the requesting entity has the necessary permissions before processing the export request. The CVSS v3.1 base score is 5.3 (medium), reflecting that the attack vector is network-based (AV:N), requires no privileges (PR:N), no user interaction (UI:N), and impacts confidentiality only (C:L) without affecting integrity or availability. The scope remains unchanged (S:U), meaning the vulnerability affects only the vulnerable component. No patches or fixes have been released at the time of publication, and no known exploits have been observed in the wild. The vulnerability exposes subscriber data, which can be leveraged for spam campaigns, phishing, or social engineering attacks. The plugin is used in WordPress environments, which are widely deployed globally, increasing the potential attack surface. The lack of authorization checks represents a common security oversight in plugin development, emphasizing the need for secure coding practices and thorough access control validation.

The primary impact of this vulnerability is the unauthorized disclosure of subscriber information, including names and email addresses. This breach of confidentiality can lead to privacy violations and damage the trust relationship between website operators and their users. Attackers can use the harvested data for targeted phishing campaigns, spam distribution, or identity theft attempts. Although the vulnerability does not affect data integrity or system availability, the exposure of personal data can have significant reputational and legal consequences, especially under data protection regulations such as GDPR or CCPA. Organizations relying on the NS Maintenance Mode for WP plugin risk non-compliance with privacy laws and potential financial penalties. The ease of exploitation—requiring no authentication or user interaction—makes this vulnerability particularly concerning for websites with large subscriber bases. Additionally, the lack of known exploits in the wild suggests that proactive mitigation can prevent exploitation before widespread attacks occur.

To mitigate CVE-2025-10638, organizations should immediately audit their use of the NS Maintenance Mode for WP plugin and restrict access to the subscriber export functionality. Plugin developers must implement strict authorization checks ensuring only authenticated and authorized users can perform subscriber exports. Website administrators should consider disabling the export feature if it is not essential or replacing the plugin with alternatives that enforce proper access controls. Monitoring web server logs for unusual or repeated access attempts to the export endpoint can help detect exploitation attempts early. Applying web application firewalls (WAFs) with rules to block unauthorized access to the export function can provide an additional layer of defense. Organizations should also review their subscriber data handling policies and ensure compliance with relevant data protection regulations. Finally, staying informed about plugin updates and applying patches promptly once available is critical to maintaining security.