CVE-2025-59030 is a vulnerability classified under CWE-276 (Incorrect Default Permissions) affecting PowerDNS Recursor versions 5.1.0, 5.2.0, and 5.3.0. The flaw allows an unauthenticated remote attacker to send a specially crafted NOTIFY query over TCP to the DNS recursor, which triggers the removal of cached DNS records. This behavior stems from improper handling of NOTIFY messages and default permissions that do not restrict such cache invalidation requests. The consequence is a denial-of-service condition where the DNS recursor loses cached entries, forcing it to perform external DNS lookups more frequently, increasing latency and potentially overwhelming upstream DNS servers. The vulnerability has a CVSS v3.1 base score of 7.5, indicating high severity, with the vector indicating network attack vector, low attack complexity, no privileges required, and no user interaction needed. The impact is limited to availability, with no direct confidentiality or integrity compromise. No patches are currently linked, and no known exploits have been reported in the wild as of the publication date. The vulnerability was reserved in early September 2025 and published in December 2025. PowerDNS Recursor is widely used in various organizations for DNS resolution, making this vulnerability relevant for operational continuity.

For European organizations, the primary impact of CVE-2025-59030 is disruption of DNS resolution services, which can degrade network performance and availability of critical applications relying on DNS. Organizations using PowerDNS Recursor as their DNS resolver or forwarder may experience increased latency and potential service outages due to forced cache misses and increased external DNS traffic. This can affect internet-facing services, internal network operations, and cloud service connectivity. The denial-of-service aspect could be exploited by attackers to cause intermittent or sustained outages, impacting business continuity and user experience. Given the essential nature of DNS in IT infrastructure, even temporary disruptions can have cascading effects on security monitoring, authentication services, and application availability. European sectors such as finance, telecommunications, and government, which rely heavily on stable DNS infrastructure, are particularly vulnerable to operational risks stemming from this vulnerability.

To mitigate CVE-2025-59030, organizations should first apply any available patches from PowerDNS once released. In the absence of patches, network-level controls should be implemented to restrict or block unsolicited TCP NOTIFY queries to PowerDNS Recursor instances. This can be achieved via firewall rules or DNS-specific access control lists that limit NOTIFY message acceptance to trusted DNS servers only. Monitoring DNS traffic for unusual NOTIFY query patterns can help detect exploitation attempts early. Additionally, configuring PowerDNS Recursor to ignore or properly authenticate NOTIFY messages, if supported, can reduce risk. Network segmentation to isolate DNS infrastructure and rate limiting DNS queries may also help mitigate impact. Regularly reviewing DNS server configurations to ensure minimal exposure and adherence to best practices for DNS security is recommended. Finally, organizations should prepare incident response plans for DNS service disruptions to minimize operational impact.