CVE-2025-66525 identifies a Missing Authorization vulnerability in Elastic Email Sender versions up to 1.2.20. This vulnerability stems from incorrectly configured access control security levels, which fail to properly restrict unauthorized users from accessing or performing actions within the Elastic Email Sender system. Missing authorization means that the system does not adequately verify whether a user has permission to execute certain operations, potentially allowing attackers to bypass security controls. Although the exact technical exploitation details are not provided, such vulnerabilities typically allow unauthorized users to send emails, modify configurations, or access sensitive information without proper credentials. The vulnerability affects the Elastic Email Sender product, a tool used for managing and dispatching bulk emails, which is critical for many organizations' communication workflows. No CVSS score has been assigned yet, and no known exploits have been reported in the wild, but the risk remains significant due to the potential for abuse. The vulnerability was published on December 9, 2025, with the issue reserved on December 4, 2025, by Patchstack. The lack of patch links indicates that fixes may not yet be available, emphasizing the need for immediate attention to access control policies and monitoring.

For European organizations, the impact of CVE-2025-66525 could be substantial, especially for those relying on Elastic Email Sender for critical email communications such as marketing, transactional emails, or internal notifications. Unauthorized access could lead to the sending of fraudulent or malicious emails, damaging organizational reputation and potentially facilitating phishing or social engineering attacks. Confidentiality could be compromised if attackers access sensitive email content or configuration data. Integrity is at risk as attackers might alter email content or sender information, undermining trust. Availability could also be affected if attackers disrupt email sending capabilities, impacting business operations. Given the widespread use of email services across Europe, organizations in sectors like finance, healthcare, and government are particularly vulnerable due to the sensitive nature of their communications. The absence of known exploits suggests a window for proactive mitigation, but also the possibility of future exploitation once attackers develop techniques.

1. Immediately review and tighten access control configurations for Elastic Email Sender to ensure that all operations require proper authorization. 2. Implement strict role-based access controls (RBAC) limiting permissions to only necessary users and services. 3. Monitor logs and audit trails for unusual or unauthorized activities related to email sending or configuration changes. 4. Restrict network access to the Elastic Email Sender interface to trusted IP addresses or VPNs to reduce exposure. 5. Apply any available patches or updates from Elastic Email as soon as they are released. 6. Conduct penetration testing focused on authorization bypass scenarios to identify and remediate weaknesses. 7. Educate administrators and users about the risks of unauthorized access and enforce strong authentication mechanisms where possible. 8. Consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block unauthorized access attempts targeting the Elastic Email Sender endpoints.