What’s Vulnerable › Vulnerabilities

CVE-2026-33594: Outgoing DoH excessive memory allocation

Description

A client can trigger excessive memory allocation by generating a lot of queries that are routed to an overloaded DoH backend, causing queries to accumulate into a buffer that will not be released until the end of the connection.

Affected products

How to fix

Upgrade to a fixed version: PowerDNS DNSdist 1.9.13, 2.0.4. Check the vendor advisory for mitigations.

References

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