What is the CVSS score of CVE-2026-33600?

CVE-2026-33600 has a CVSS 3.1 base score of 4.4 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.0%.

Is there a patch available for CVE-2026-33600?

Yes, a patch is available for CVE-2026-33600. Update the affected software to the latest version immediately.

PowerDNS Recursor CVE-2026-33600

EUVD-2026-24731 MEDIUM

NULL Pointer Dereference (CWE-476)

2026-04-22 OX

Denial Of Service Null Pointer Dereference Suse Powerdns Recursor

4.4

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

4.4 MEDIUM

AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H

SUSE

MEDIUM

qualitative

Primary rating from NVD.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

High

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Patch released

Apr 27, 2026 - 16:59 nvd

Patch available

Analysis Generated

Apr 22, 2026 - 13:09 vuln.today

Patch available

Apr 22, 2026 - 11:16 EUVD

EUVD ID Assigned

Apr 22, 2026 - 10:00 euvd

EUVD-2026-24731

Analysis Generated

Apr 22, 2026 - 10:00 vuln.today

CVE Published

Apr 22, 2026 - 09:33 nvd

MEDIUM 4.4

DescriptionCVE.org

An RPZ sent by a malicious authoritative server can result in a null pointer dereference, caused by a missing consistency check and leading to a denial of service.

AnalysisAI

Denial of service in PowerDNS Recursor occurs when processing a malicious Response Policy Zone (RPZ) from an authoritative server, triggering a null pointer dereference due to missing validation logic. Versions 5.2.0-5.2.8, 5.3.0-5.3.5, and 5.4.0 are affected. An authenticated remote attacker controlling an authoritative nameserver can crash the Recursor service by sending a specially crafted RPZ response, requiring high privilege level (PR:H) and complex attack conditions (AC:H) as mitigating factors.

Technical ContextAI

PowerDNS Recursor is a caching DNS resolver that processes DNS responses and policies. Response Policy Zones (RPZs) are a BIND-compatible mechanism for applying dynamic DNS policies by querying a special zone served by an authoritative server. The vulnerability stems from insufficient validation when parsing RPZ data received from authoritative servers-specifically, a missing consistency check that should prevent null pointer construction. The null dereference occurs during RPZ processing, causing an unhandled exception that terminates the Recursor process. CWE classification is not provided, but the root cause aligns with CWE-476 (Null Pointer Dereference) and CWE-252 (Unchecked Return Value).

RemediationAI

Upgrade PowerDNS Recursor to version 5.2.9, 5.3.6, or 5.4.1 depending on your current branch-these releases include the null pointer consistency check fix. For environments unable to patch immediately, disable RPZ functionality if operationally feasible by removing RPZ zone definitions from the Recursor configuration file (typically recursor.conf) and restarting the service; this eliminates the attack surface at the cost of losing dynamic policy enforcement. Alternatively, restrict queries to RPZ zones from trusted authoritative servers only by implementing network-level access controls (firewall rules limiting outbound DNS queries to known-good RPZ providers) and validating TSIG signatures if the authoritative server supports authenticated RPZ delivery. Consult the PowerDNS security advisory at https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-powerdns-2026-03.html for version-specific guidance and confirmation of patch applicability.