CVE-2026-45674: Netty resolver dns Netty Vulnerable To DNS Cache Vulnerability

HIGH
Advisory Identifier: GHSA-676x-f7gg-47vc
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CVSS 8.7
CWE-345 CWE-346
Published
Advisory Summary

CVE-2026-45674 is a HIGH (CVSS 8.7) netty vulnerable to dns cache vulnerability (CWE-345: Insufficient Verification of Data Authenticity) affecting Netty resolver dns libraries in the Maven ecosystem. The issue involves netty vulnerable to dns cache poisoning via missing bailiwick checks in cname records. Remediation is available by upgrading affected packages to version 4.2.15.Final, 4.1.135.Final.

CVE-2026-45674 at a Glance

CVE Identifier CVE-2026-45674
GHSA Identifier GHSA-676x-f7gg-47vc
Severity HIGH
CVSS v3.1 Base Score 8.7
CWE Classification CWE-345: Insufficient Verification of Data Authenticity
Affected Product Netty resolver dns
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.7

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2026-45674

To remediate this vulnerability, upgrade all affected Netty resolver dns dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

io.netty:netty-resolver-dns fixed: 4.2.15.Final 
<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-resolver-dns</artifactId>
    <version>4.2.15.Final</version>
</dependency>
io.netty:netty-resolver-dns fixed: 4.1.135.Final 
<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-resolver-dns</artifactId>
    <version>4.1.135.Final</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=io.netty

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-45674, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=io.netty

Analyze the terminal output to locate any version of Netty resolver dns in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.2.15.Final), your application is affected.

Note: The mvn dependency:tree -Dincludes=io.netty command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-345: Insufficient Verification of Data Authenticity, where the product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. In Netty resolver dns, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary Netty's DnsResolveContext fails to validate the origin (bailiwick) of CNAME records in DNS responses. ### Details In `io.netty.resolver.dns.DnsResolveContext#buildAliasMap`, the resolver processes the ANSWER section of a DNS response and blindly caches all CNAME records it finds. According to https://datatracker.ietf.org/doc/html/rfc5452#section-6 ``` Care must be taken to only accept data if it is known that the originator is authoritative for the QNAME or a parent of the QNAME. One very simple way to achieve this is to only accept data if it is part of the domain for which the query was intended. ``` ### Impact DNS Cache Poisoning (Bailiwick Bypass). Any application using Netty's DNS resolver is impacted.

CVE-2026-45674 Affected Netty resolver dns Versions

2 component(s)
Fixed Versions:
4.2.15.Final4.1.135.Final
Product / Package Ecosystem Affected Versions Fixed Version
io.netty:netty-resolver-dns
maven/io.netty/netty-resolver-dns
Maven
≥ 4.2.0.Final
< 4.2.15.Final
4.2.15.Final
io.netty:netty-resolver-dns
maven/io.netty/netty-resolver-dns
Maven
< 4.1.135.Final
4.1.135.Final

References

GitHub Advisory / Wiki ADVISORY
https://github.com/netty/netty/security/advisories/GHSA-676x-f7gg-47vc
NVD — CVE-2026-45674 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-45674
Netty resolver dns Security Information SECURITY
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45674.json
Netty resolver dns Release RELEASE
https://github.com/netty/netty/releases/tag/netty-4.2.15.Final
Netty resolver dns Release RELEASE
https://github.com/netty/netty/releases/tag/netty-4.1.135.Final
Netty resolver dns Source Repository REPOSITORY
https://github.com/netty/netty
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2488400
Netty resolver dns Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2026-45674
access.redhat.com/errata/rhsa-2026:65... WEB
https://access.redhat.com/errata/RHSA-2026:65126
access.redhat.com/errata/rhsa-2026:62... WEB
https://access.redhat.com/errata/RHSA-2026:62260
access.redhat.com/errata/rhsa-2026:54... WEB
https://access.redhat.com/errata/RHSA-2026:54435
access.redhat.com/errata/rhsa-2026:53... WEB
https://access.redhat.com/errata/RHSA-2026:53806
access.redhat.com/errata/rhsa-2026:53... WEB
https://access.redhat.com/errata/RHSA-2026:53646
access.redhat.com/errata/rhsa-2026:53... WEB
https://access.redhat.com/errata/RHSA-2026:53645
access.redhat.com/errata/rhsa-2026:53... WEB
https://access.redhat.com/errata/RHSA-2026:53644
access.redhat.com/errata/rhsa-2026:50... WEB
https://access.redhat.com/errata/RHSA-2026:50085
access.redhat.com/errata/rhsa-2026:49... WEB
https://access.redhat.com/errata/RHSA-2026:49701
access.redhat.com/errata/rhsa-2026:49... WEB
https://access.redhat.com/errata/RHSA-2026:49700
access.redhat.com/errata/rhsa-2026:48... WEB
https://access.redhat.com/errata/RHSA-2026:48151
access.redhat.com/errata/rhsa-2026:41... WEB
https://access.redhat.com/errata/RHSA-2026:41951
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37390
access.redhat.com/errata/rhsa-2026:34... WEB
https://access.redhat.com/errata/RHSA-2026:34608
access.redhat.com/errata/rhsa-2026:26... WEB
https://access.redhat.com/errata/RHSA-2026:26586
access.redhat.com/errata/rhsa-2026:26... WEB
https://access.redhat.com/errata/RHSA-2026:26018
access.redhat.com/errata/rhsa-2026:26... WEB
https://access.redhat.com/errata/RHSA-2026:26017

Frequently Asked Questions

What is CVE-2026-45674?
CVE-2026-45674 is a security vulnerability in Netty resolver dns involving Netty Vulnerable to DNS Cache Poisoning via Missing Bailiwick Checks in CNAME Records under CWE-345: Insufficient Verification of Data Authenticity.
Which Netty resolver dns versions are affected?
Affected versions include releases prior to 4.2.15.Final, 4.1.135.Final across affected packages: io.netty:netty-resolver-dns.
What version fixes CVE-2026-45674?
Upgrading to 4.2.15.Final, 4.1.135.Final (or the latest patched release for your respective branch) resolves the vulnerability.
Is netty-resolver-dns affected?
Yes, io.netty:netty-resolver-dns is affected in releases prior to 4.2.15.Final, 4.1.135.Final. Upgrade your dependency to 4.2.15.Final, 4.1.135.Final or later.
What is the CVSS score of CVE-2026-45674?
CVE-2026-45674 has a CVSS v3.1 base score of 8.7 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N.
What CWE is associated with CVE-2026-45674?
CVE-2026-45674 is classified under CWE-345: Insufficient Verification of Data Authenticity (The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.).
How can I check Maven dependencies for CVE-2026-45674?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=io.netty'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
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  "id" : "GHSA-676x-f7gg-47vc",
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  "published" : "2026-06-08T23:02:26Z",
  "aliases" : [ "CVE-2026-45674" ],
  "summary" : "Netty Vulnerable to DNS Cache Poisoning via Missing Bailiwick Checks in CNAME Records",
  "details" : "### Summary\nNetty's DnsResolveContext fails to validate the origin (bailiwick) of CNAME records in DNS responses.\n\n### Details\nIn `io.netty.resolver.dns.DnsResolveContext#buildAliasMap`, the resolver processes the ANSWER section of a DNS response and blindly caches all CNAME records it finds.\n\nAccording to https://datatracker.ietf.org/doc/html/rfc5452#section-6 \n\n```\nCare must be taken to only accept\n   data if it is known that the originator is authoritative for the\n   QNAME or a parent of the QNAME.\n   One very simple way to achieve this is to only accept data if it is\n   part of the domain for which the query was intended.\n```\n\n### Impact\nDNS Cache Poisoning (Bailiwick Bypass). Any application using Netty's DNS resolver is impacted.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N"
  } ],
  "affected" : [ {
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    },
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    "database_specific" : {
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    }
  }, {
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    },
    "ranges" : [ {
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  "references" : [ {
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  }, {
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  }, {
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    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2488400"
  }, {
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  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:65126"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:62260"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:54435"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:53806"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:53646"
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    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:53644"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:50085"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:49701"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:49700"
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    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:48151"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:41951"
  }, {
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    "url" : "https://access.redhat.com/errata/RHSA-2026:37390"
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    "url" : "https://access.redhat.com/errata/RHSA-2026:34608"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:26586"
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  "database_specific" : {
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    "severity" : "HIGH",
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    "github_reviewed_at" : "2026-06-08T23:02:26Z",
    "nvd_published_at" : "2026-06-12T15:16:27Z"
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}