CVE-2025-64218 is a security vulnerability identified in the WP Chill Passster plugin for WordPress, affecting all versions up to and including 4.2.19. Passster is a content protection plugin that restricts access to certain content on WordPress sites. The vulnerability involves the insertion of sensitive information into data sent by the plugin, which can then be retrieved by an attacker. This means that data intended to be protected or hidden by Passster may be exposed through the plugin’s data transmission mechanisms. The vulnerability does not require authentication or user interaction, which significantly lowers the barrier to exploitation. Although no public exploits have been reported yet, the flaw could allow unauthorized parties to access confidential or sensitive information embedded in the plugin’s sent data, potentially leading to data breaches or leakage of protected content. The lack of a CVSS score indicates that the vulnerability is newly published and not yet fully assessed, but the nature of the flaw suggests a significant confidentiality impact. The vulnerability affects WordPress sites using Passster, a plugin popular among European organizations for content protection, especially in sectors like education, media, and e-commerce. The absence of patch links suggests that a fix may still be pending or recently released, so organizations should monitor vendor communications closely. The vulnerability was reserved in late October 2025 and published in December 2025, indicating recent discovery and disclosure.

For European organizations, the primary impact of CVE-2025-64218 is the potential unauthorized disclosure of sensitive or confidential information protected by the Passster plugin. This could include intellectual property, personal data, or proprietary content, leading to reputational damage, regulatory non-compliance (e.g., GDPR violations), and financial losses. Since the vulnerability does not require authentication, attackers can exploit it remotely without credentials, increasing the risk of widespread data leakage. Organizations relying on Passster for content protection in sectors such as education, media, and e-commerce are particularly vulnerable. The exposure of sensitive data could also facilitate further attacks, such as phishing or social engineering. Additionally, the breach of confidentiality could undermine trust in digital services and platforms that use Passster. The impact on availability and integrity is minimal, as the vulnerability primarily affects confidentiality. However, the scope of affected systems is broad given WordPress’s popularity and Passster’s usage in Europe.

1. Monitor WP Chill’s official channels for patches addressing CVE-2025-64218 and apply updates immediately once available. 2. In the interim, consider disabling the Passster plugin or restricting its use to non-sensitive content until a fix is deployed. 3. Conduct a thorough audit of all content protected by Passster to identify any potentially exposed sensitive information. 4. Implement network-level controls such as Web Application Firewalls (WAFs) to detect and block suspicious requests targeting the plugin’s data transmission endpoints. 5. Review and harden WordPress site configurations to minimize unnecessary data exposure, including limiting access to administrative and plugin-related endpoints. 6. Educate site administrators about the vulnerability and encourage regular security assessments of WordPress plugins. 7. Employ data encryption in transit (TLS) and at rest to reduce the risk of data interception and leakage. 8. Consider alternative content protection mechanisms with a strong security track record until the vulnerability is resolved.