Memory Allocation Vulnerability in PowerDNS DoH Client

CVE-2026-33594

What is CVE-2026-33594?

A vulnerability exists in PowerDNS DNSDist where clients can inadvertently trigger excessive memory allocation. This occurs when multiple queries are sent to an overloaded DNS-over-HTTPS (DoH) backend, leading to a backlog of queries that cannot be released until the connection is closed. This situation may result in degraded performance and increased resource consumption. It is crucial for users to examine their configurations and monitor their DNS traffic to mitigate potential impacts.

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