Threats affecting pkg:github/pdns-recursor

RRSIGs with too few labels can lead to bypass of DNSSEC wildcard validation

The issue is a DNSSEC validation bypass where wildcard expansion proofs (NSEC/NSEC3 records) are accepted without signature validation when the wildcard answer is a CNAME or DNAME record.

If the auth responds very slowly and the records expire in between, the capping of TTLs is not enforced for lack of data. This does not happen on regular resolve as then then the child records are used immediately if not expired and thus valid, or the records are expired, and in that case not used. So this case can only happen if almost expired records are used to refresh the authoritative NS records.

Spoofing replies to Recursor might mark an IP of an authoritative server as not supporting EDNS, causing valdiation of DNSSEC records served by that server to fail.

This fix provides extra hardening for the 5.4.x branch by doing extra validation of incoming answers from authoritative servers.

An invalid zone might pass ZONEMD validation while it should not. This is only relevant if ZoneToCache is configured with ZONEMD validation.

Incomplete validation of the SOA record present in a catalog zone might lead to a crash.

A malicious authoritative server can send a crafted zone via the ZoneToCache function that leads to a crash of the Recursor due to insuffcient input validation.

ECS zero scoped answers are stored in the packet cache while they should not. This impacts only configurations that have ECS enabled;

A malicious authoritative server can send a crafted zone via the ZoneToCache function that leads to cache poisoning.

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.

CVE-2026-33257 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 by the vendor. No known exploits are reported in the wild at this time.

CVE-2026-33256 is a medium severity vulnerability in PowerDNS Recursor versions 5.2.0, 5.3.0, and 5.4.0. It involves allocation of resources without limits or throttling in the internal web server, which is disabled by default. An attacker can send a web request that triggers unlimited memory allocation, potentially causing a denial of service. No official patch or remediation guidance is currently available.

CVE-2026-33601 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 when the zoneToCache function processes a malicious authoritative server's zone data without proper consistency checks. This flaw can cause a denial of service by crashing the service. There is no confirmed patch or official remediation available at this time, and no known exploits have been reported in the wild.

CVE-2026-33600 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 a malicious authoritative server sending a crafted RPZ (Response Policy Zone) that lacks a necessary consistency check. This flaw can cause the PowerDNS Recursor to crash, resulting in a denial of service condition. There is no indication of confidentiality or integrity impact, and no known exploits are reported in the wild.

Crafted delegations or IP fragments can poison cached delegations in Recursor.