CVE-2026-33610Network attack vector

Service interruption via leaked update-forwarding descriptors

Published Apr 22, 2026 · Updated Apr 22, 2026

Resource exhaustion in PowerDNS Authoritative Server 4.9.0 through 4.9.13 and 5.0.0 through 5.0.3 allows remote attackers to halt DNS service. The DNS-update forwarding path in rfc2136handler.cc leaves outbound descriptors open while processing a primary server response, allowing repeated forwarding to consume the process limit. Exploitation requires a secondary server to forward a DNS update to a rogue primary; the resulting descriptor exhaustion interrupts availability without reported data access or modification.

CVSS severity7.5
High
EPSS probability0.39%
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 4.9.0 through 4.9.13 and 5.0.0 through 5.0.3 allows remote attackers to halt DNS service. The DNS-update forwarding path in rfc2136handler.cc leaves outbound descriptors open while processing a primary server response, allowing repeated forwarding to consume the process limit. Exploitation requires a secondary server to forward a DNS update to a rogue primary; the resulting descriptor exhaustion interrupts availability without reported data access or modification.

The record

CVE
CVE-2026-33610
Published
Apr 22, 2026
Updated
Apr 22, 2026
Vendor
PowerDNS
Product
PowerDNS Authoritative Server
Classifications
CWE-400, 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

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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

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.9UbuntuCVSS:3.1/AV:N/AC:H/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
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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