CVE-2025-9895 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the Notification Bar plugin for WordPress developed by umarbajwa. This vulnerability exists in all versions up to and including 2.2 of the plugin. The root cause is the absence or incorrect implementation of nonce validation on the 'subscriber-list-empty.php' endpoint. Nonces are security tokens used to verify that a request is legitimate and originates from an authorized user. Without proper nonce validation, an attacker can craft a malicious request that, when executed by an authenticated site administrator (e.g., by clicking a link or visiting a malicious webpage), triggers the emptying of the subscriber list. This action can be performed without the attacker needing any authentication themselves, relying solely on social engineering to trick the administrator into executing the request. The vulnerability impacts the integrity of the subscriber list data by allowing unauthorized deletion, but it does not affect confidentiality or availability directly. The CVSS v3.1 base score is 4.3 (medium severity), reflecting the network attack vector, low attack complexity, no privileges required, but requiring user interaction. There are no known exploits in the wild at the time of publication. The vulnerability is specific to the Notification Bar plugin, a WordPress add-on used to display notification bars and manage subscriber lists on websites. Since WordPress is widely used across Europe, and this plugin may be installed on many sites, the vulnerability poses a risk to website administrators who rely on this plugin for subscriber management.

For European organizations, especially those using WordPress with the umarbajwa Notification Bar plugin, this vulnerability can lead to unauthorized deletion of subscriber lists. This can disrupt marketing campaigns, reduce customer engagement, and cause reputational damage due to loss of subscriber data. While the vulnerability does not directly compromise sensitive data or website availability, the integrity loss of subscriber lists can have downstream business impacts, such as loss of revenue or trust. Organizations with heavy reliance on email marketing or subscriber notifications are particularly at risk. Additionally, the need for user interaction (administrator clicking a malicious link) means that phishing or social engineering campaigns could be used to exploit this vulnerability, which is a common attack vector in Europe. The impact is more pronounced for organizations with less mature security awareness or those lacking robust email filtering and user training.

To mitigate this vulnerability, organizations should immediately update the Notification Bar plugin to a patched version once available. In the absence of an official patch, administrators can implement manual nonce validation by modifying the 'subscriber-list-empty.php' file to include proper WordPress nonce checks using functions like wp_verify_nonce(). Additionally, organizations should enforce strict user awareness training to prevent administrators from clicking suspicious links or visiting untrusted websites. Employing web application firewalls (WAFs) that can detect and block CSRF attack patterns may provide temporary protection. Limiting administrator access and using multi-factor authentication can reduce the risk of successful exploitation. Regular backups of subscriber lists should be maintained to enable recovery in case of data loss. Monitoring administrative actions and logs for unusual activity can help detect attempted exploitation early.