CVE-2025-2560 is a stored Cross-Site Scripting (XSS) vulnerability identified in the Ninja Forms WordPress plugin prior to version 3.10.1. The root cause is the plugin's failure to properly sanitize and escape certain settings fields, which allows high-privilege users, such as administrators, to inject malicious JavaScript code into the plugin's stored data. This vulnerability is notable because it bypasses the typical WordPress security control of the unfiltered_html capability, meaning that even in environments where this capability is restricted (such as multisite WordPress installations), the stored XSS can still be introduced by privileged users. The attack vector requires network access (remote) and high privileges (admin-level), with user interaction needed to trigger the malicious payload. The vulnerability impacts confidentiality and integrity by potentially allowing attackers to execute arbitrary scripts in the context of administrative users, which could lead to session hijacking, privilege escalation, or defacement. However, it does not directly affect availability. The CVSS v3.1 base score is 4.8 (medium severity), reflecting the moderate impact and exploitation complexity. No public exploits are known at this time, but the vulnerability is published and recognized by WPScan and CISA. The lack of patch links suggests that users should monitor for official updates from the Ninja Forms developers and apply them promptly once available.

For European organizations, this vulnerability poses a risk primarily to websites using the Ninja Forms plugin on WordPress, especially those with multiple administrators or multisite configurations. Exploitation could allow an attacker with administrative access to inject malicious scripts that execute in the browsers of other administrators or privileged users, potentially leading to session hijacking, theft of sensitive data, or unauthorized changes to site content. This could undermine the integrity of corporate websites, customer-facing portals, or internal tools relying on WordPress. Given the widespread use of WordPress in Europe for business and government websites, the impact could be significant if exploited in high-profile targets. However, the requirement for high privileges limits the attack surface to insiders or compromised admin accounts. The vulnerability does not directly disrupt service availability but could lead to reputational damage and compliance issues under GDPR if personal data is exposed or manipulated.

European organizations should immediately verify the version of Ninja Forms installed on their WordPress sites and upgrade to version 3.10.1 or later once available. Until a patch is released, administrators should restrict the number of users with high privileges and enforce strong authentication controls, including multi-factor authentication, to reduce the risk of account compromise. Implement Content Security Policy (CSP) headers to limit the impact of injected scripts. Regularly audit plugin settings and user inputs for suspicious content. In multisite environments, review and tighten capability assignments to prevent unauthorized privilege escalation. Additionally, monitor logs for unusual administrative activity and consider deploying Web Application Firewalls (WAFs) with rules to detect and block XSS payloads targeting Ninja Forms. Educate administrators about the risk of stored XSS and safe input handling practices.