CVE-2026-64194Network attack vector

Resource exhaustion via unbounded compression-pointer recursion

Published Jul 20, 2026 · Updated Jul 20, 2026

Uncontrolled recursion in NLnet Labs Net::DNS 1.55 and earlier allows remote attackers to exhaust resources with crafted DNS packets. Net::DNS::DomainName::decode follows each fresh backward RFC 1035 compression pointer recursively without enforcing a depth limit. Applications that pass untrusted wire data to Net::DNS::Packet->new are exposed; long chains cause a memory spike and terminate processes with low heap limits.

CVSS severity7.5
High
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled recursion in NLnet Labs Net::DNS 1.55 and earlier allows remote attackers to exhaust resources with crafted DNS packets. Net::DNS::DomainName::decode follows each fresh backward RFC 1035 compression pointer recursively without enforcing a depth limit. Applications that pass untrusted wire data to Net::DNS::Packet->new are exposed; long chains cause a memory spike and terminate processes with low heap limits.

The record

CVE
CVE-2026-64194
Published
Jul 20, 2026
Updated
Jul 20, 2026
Vendor
NLnet Labs
Product
Net::DNS
Classifications
CWE-674, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 20, 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=0 <=1.55

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

NLnet Labs · Net::DNSversion=0 <=1.55

Published CVSS scores

7.5CISA-ADPCVSS: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.

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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-674Uncontrolled Recursion
T1499Endpoint Denial of Service

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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