CVE-2026-33257Network attack vector

Service interruption via unlimited web-request memory allocation

Published Apr 22, 2026 · Updated Apr 22, 2026

Resource exhaustion in PowerDNS Authoritative Server, Recursor, and DNSdist allows remote attackers to interrupt service via crafted HTTP requests. The published advisories state only that the internal web server allocates unlimited memory while processing a crafted request; no lower-level code locus or input field is disclosed. Exploitation requires the disabled-by-default web server to be enabled and reachable through its default loopback ACL or a broader configured ACL, and the documented consequence is availability loss without system compromise.

CVSS severity5.3
Medium
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in PowerDNS Authoritative Server, Recursor, and DNSdist allows remote attackers to interrupt service via crafted HTTP requests. The published advisories state only that the internal web server allocates unlimited memory while processing a crafted request; no lower-level code locus or input field is disclosed. Exploitation requires the disabled-by-default web server to be enabled and reachable through its default loopback ACL or a broader configured ACL, and the documented consequence is availability loss without system compromise.

The record

CVE
CVE-2026-33257
Published
Apr 22, 2026
Updated
Apr 22, 2026
Vendor
PowerDNS
Product
PowerDNS Authoritative Server
Classifications
CWE-770, CAPEC-130, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.9.0 <4.9.14
  2. Affected versionversion=5.0.0 <5.0.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

PowerDNS · PowerDNS Authoritative Serverversion=4.9.0 <4.9.14; version=5.0.0 <5.0.4
PowerDNS · PowerDNS Recursorversion=5.2.0 <5.2.9; version=5.3.0 <5.3.6; version=5.4.0 <5.4.1
PowerDNS · DNSdistversion=1.9.0 <1.9.13; version=2.0.0 <2.0.4

Published CVSS scores

5.3Open-XchangeCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
CAPEC-130Excessive Allocation
T1499.003Application Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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