CVE-2026-33611Network attack vector

Service interruption via malformed SVCB record generation

Published Apr 22, 2026 · Updated Apr 22, 2026

Data corruption in PowerDNS Authoritative Server 4.9.0 through 4.9.13 and 5.0.0 through 5.0.3 allows remote authenticated users to interrupt service. The SVCB/ALPN parsing paths in dnswriter.cc and rcpgenerator.cc fail to reject crafted values before generating malformed HTTPS or SVCB record data. Exploitation requires a trusted REST API operator and the LMDB backend; the malformed data can corrupt the database and interrupt authoritative DNS service.

CVSS severity6.5
Medium
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Data corruption in PowerDNS Authoritative Server 4.9.0 through 4.9.13 and 5.0.0 through 5.0.3 allows remote authenticated users to interrupt service. The SVCB/ALPN parsing paths in dnswriter.cc and rcpgenerator.cc fail to reject crafted values before generating malformed HTTPS or SVCB record data. Exploitation requires a trusted REST API operator and the LMDB backend; the malformed data can corrupt the database and interrupt authoritative DNS service.

The record

CVE
CVE-2026-33611
Published
Apr 22, 2026
Updated
Apr 22, 2026
Vendor
PowerDNS
Product
PowerDNS Authoritative Server
Classifications
CWE-190, T1565.001
Attack vector
network
Privileges
admin

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 privilegesadmin

What is affected?

PowerDNS · PowerDNS Authoritative Serverversion=4.9.0 <4.9.14; version=5.0.0 <5.0.4

Published CVSS scores

6.5Open-XchangeCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
4.9NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
T1565.001Stored Data Manipulation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo