CVE-2026-73508Network attack vector

Application denial of service via DNS buffer leak

Published Aug 13, 2026 · Updated Aug 13, 2026

Resource exhaustion in Netty before 4.1.136.Final and 4.2.0 through 4.2.15.Final allows remote attackers to interrupt applications via DNS packets. AbstractDnsRecord passes decoded names to IDN.toASCII before owning retained ByteBuf content, while decodeRecord and decompressDomainName fail to release allocated or retained buffers when name validation throws. Any network-reachable application using DnsRecordDecoder can gradually exhaust direct memory under sustained malformed traffic and become unresponsive.

CVSS severity5.3
Medium
EPSS probability0.33%
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 Netty before 4.1.136.Final and 4.2.0 through 4.2.15.Final allows remote attackers to interrupt applications via DNS packets. AbstractDnsRecord passes decoded names to IDN.toASCII before owning retained ByteBuf content, while decodeRecord and decompressDomainName fail to release allocated or retained buffers when name validation throws. Any network-reachable application using DnsRecordDecoder can gradually exhaust direct memory under sustained malformed traffic and become unresponsive.

The record

CVE
CVE-2026-73508
Published
Aug 13, 2026
Updated
Aug 13, 2026
Vendor
The Netty Project
Product
Netty
Classifications
CWE-772, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 13, 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=< 4.1.136.Final
  2. Affected versionversion=>= 4.2.0.Final, < 4.2.16.Final

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Netty Project · Nettyversion=< 4.1.136.Final; version=>= 4.2.0.Final, < 4.2.16.Final

Published CVSS scores

5.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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 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-772Missing Release of Resource after Effective Lifetime
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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