PowerDNS vulnerabilities and threats

Insufficient Validation of Names During AXFR

Insufficient Validation of Member Zone Data May Cause Catalog Zone Transfer to Fail

An operator allowed to use the REST API can cause the Authoritative server to produce invalid HTTPS or SVCB record data, which can in turn cause LMDB database corruption, if using the LMDB backend.

A rogue primary server may cause file descriptor exhaustion and eventually a denial of service, when a PowerDNS secondary server forwards a DNS update request to it.

Incomplete escaping of LDAP queries when running with 8bit-dns enabled allows users to perform queries of internal domain subtrees.

An attacker can send a notify request that causes a new secondary domain to be added to the bind backend, but causes said backend to update its configuration to an invalid one, leading to the backend no longer able to run on the next restart, requiring manual operation to fix it.

A client can trigger a divide by zero error leading to crash by sending a crafted DNSCrypt query.

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.

A client can trigger excessive memory allocation by generating a lot of errors responses over a single DoQ and DoH3 connection, as some resources were not properly released until the end of the connection.

PRSD detection denial of service

A client might theoretically be able to cause a mismatch between queries sent to a backend and the received responses by sending a flood of perfectly timed queries that are routed to a TCP-only or DNS over TLS backend.

A cached crafted response can cause an out-of-bounds read if custom Lua code calls getDomainListByAddress() or getAddressListByDomain() on a packet cache.

A rogue backend can send a crafted SVCB response to a Discovery of Designated Resolvers request, when requested via either the autoUpgrade (Lua) option to newServer or auto_upgrade (YAML) settings. DDR upgrade is not enabled by default.

A rogue backend can send a crafted UDP response with a query ID off by one related to the maximum configured value, triggering an out-of-bounds write leading to a denial of service.

CVE-2026-33254 is a vulnerability in PowerDNS DNSdist where an attacker can cause unlimited memory allocation by creating many concurrent DoQ or DoH3 connections, resulting in a denial of service. Both DoQ and DoH3 are disabled by default in DNSdist. The vulnerability affects versions 1.9.0 and 2.0.0. No official patch or remediation guidance is currently available.

CVE-2026-33262 is a medium severity vulnerability in PowerDNS Recursor versions 5.2.0, 5.3.0, and 5.4.0. It involves a null pointer dereference triggered by specially crafted replies due to a missing consistency check, resulting in a denial of service condition. Cookies are disabled by default in the affected product. There is no confirmed patch or official remediation available at this time.

CVE-2026-33261 is a medium severity vulnerability in PowerDNS Recursor versions 5.2.0, 5.3.0, and 5.4.0. It involves a missing support for integrity checks during a zone transition from NSEC to NSEC3, which can cause an internal inconsistency leading to a denial of service (DoS). The vulnerability does not impact confidentiality or integrity but affects availability. There is no known exploit in the wild and no official patch or remediation guidance has been provided yet.

CVE-2026-33260 is a medium severity vulnerability in PowerDNS Authoritative versions 4.9.0 and 5.0.0. It allows an attacker to send a web request that triggers unlimited memory allocation in the internal web server, potentially causing a denial of service. The internal web server is disabled by default, which reduces the attack surface. There is no official patch or remediation level currently provided. No known exploits are reported in the wild.

CVE-2026-33259 is a use-after-free vulnerability in PowerDNS Recursor versions 5.2.0, 5.3.0, and 5.4.0. It occurs when many concurrent transfers of the same Response Policy Zone (RPZ) happen, potentially leading to inconsistent RPZ data, use-after-free conditions, or a crash of the recursor. Such concurrent transfers typically only occur if the RPZ provider malfunctions. The vulnerability has a medium severity rating with a CVSS score of 5.

CVE-2026-33258 is a medium severity vulnerability in PowerDNS Recursor versions 5.2.0, 5.3.0, and 5.4.0. It allows an attacker to cause excessive allocation of resources in the negative and aggressive NSEC(3) caches by publishing and querying a specially crafted DNS zone. This can lead to resource exhaustion and potential denial of service conditions. There is no confirmed patch or official remediation available at this time.