CVE-2025-62943 is a stored Cross-site Scripting (XSS) vulnerability identified in the WordPress plugin 'Next Page, Not Next Post' developed by Matt McInvale. This plugin, which facilitates navigation on WordPress sites, improperly neutralizes user-supplied input during web page generation, allowing malicious scripts to be stored and later executed in the context of users visiting the affected pages. The vulnerability affects all versions up to and including 0.3.0. The CVSS 3.1 base score is 5.4, indicating a medium severity, with an attack vector of network (remote exploitation), low attack complexity, requiring low privileges and user interaction, and impacting confidentiality and integrity with a scope change. Specifically, an attacker with a low-privileged account can inject malicious JavaScript payloads that execute when other users view the compromised content, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim. The vulnerability does not impact availability. No public exploits have been reported yet, but the presence of stored XSS in a widely used plugin poses a significant risk if left unpatched. The lack of available patches at the time of publication necessitates immediate attention to mitigation strategies. Stored XSS vulnerabilities are particularly dangerous because the malicious payload persists on the server and can affect multiple users over time. The vulnerability was reserved on October 24, 2025, and published on October 27, 2025, indicating recent discovery and disclosure.

For European organizations, this vulnerability poses a moderate risk primarily to websites using the 'Next Page, Not Next Post' WordPress plugin. Exploitation can lead to unauthorized disclosure of sensitive information such as session cookies or personal data, undermining user trust and potentially violating GDPR requirements. Attackers could leverage the vulnerability to perform actions on behalf of authenticated users, leading to data integrity issues or unauthorized changes on websites. While availability is not affected, the reputational damage and potential regulatory penalties from data breaches could be significant. Organizations operating e-commerce, government, or media websites using this plugin are at higher risk due to the value of their user data and the potential impact of compromised user sessions. The requirement for user interaction and low privileges reduces the ease of exploitation but does not eliminate the threat, especially in environments with many authenticated users. The absence of known exploits in the wild provides a window for proactive mitigation before widespread attacks occur.

1. Monitor for official patches or updates from the plugin developer and apply them immediately once available. 2. Until patches are released, implement strict input validation and output encoding on all user-supplied data within the plugin's scope to prevent script injection. 3. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts on affected web pages. 4. Limit the number of users with privileges to add or edit content that could be exploited, and enforce the principle of least privilege. 5. Conduct regular security audits and scanning for XSS vulnerabilities on WordPress sites, focusing on plugins and custom code. 6. Educate users and administrators about the risks of clicking on suspicious links or interacting with untrusted content. 7. Consider using Web Application Firewalls (WAFs) with rules designed to detect and block XSS payloads targeting this plugin. 8. Review and harden WordPress security configurations, including disabling unnecessary plugins and features.