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Fencer Vulns
high 7.5

CVE-2026-42579 json

Netty: DNS Codec Input Validation Bypass in Netty (Encoder + Decoder)

published 2026-05-07 6 mo ago modified 2026-09-18 51 d ago also GHSA-cm33-6792-r9fm , EUVD-2026-30122

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 63%
public exploits
0
none known

Summary

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's DNS codec does not enforce RFC 1035 domain name constraints during either encoding or decoding. This creates a bidirectional attack surface: malicious DNS responses can exploit the decoder, and user-influenced hostnames can exploit the encoder. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

Patch / fix

  • maven io.netty:netty-codec-dns 4.1.133.Final, 4.2.13.Final
  • Red Hat Cryostat 4 on RHEL 9 4.2.0-10
  • Red Hat Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7 0:1.5.26-2.Final_redhat_00001.1.el7eap, 0:1.10.0-46.Final_redhat_00044.1.el7eap, 0:2.2.40-2.SP3_redhat_00001.1.el7eap, 0:2.3.14-11.SP11_redhat_00001.1.el7eap, 0:2.5.5-24.SP12_redhat_00016.1.el7eap, 0:2.5.5-30.SP12_redhat_00020.1.el7eap, 0:2.16.0-22.redhat_00057.1.el7eap, 0:2.18.8-1.redhat_00003.1.el7eap, 0:4.1.135-1.Final_redhat_00001.1.el7eap, 0:5.0.31-3.SP2_redhat_00001.1.el7eap, 0:7.4.25-2.GA_redhat_00001.1.el7eap
  • Red Hat Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8 0:1.5.26-2.Final_redhat_00001.1.el8eap, 0:1.10.0-46.Final_redhat_00044.1.el8eap, 0:2.2.40-1.SP3_redhat_00001.1.el8eap, 0:2.3.14-11.SP11_redhat_00001.1.el8eap, 0:2.5.5-24.SP12_redhat_00016.1.el8eap, 0:2.5.5-30.SP12_redhat_00020.1.el8eap, 0:2.16.0-22.redhat_00057.1.el8eap, 0:2.18.8-1.redhat_00003.1.el8eap, 0:4.1.135-1.Final_redhat_00001.1.el8eap, 0:5.0.31-3.SP2_redhat_00001.1.el8eap, 0:7.4.25-2.GA_redhat_00001.1.el8eap
  • Red Hat Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 9 0:1.5.26-2.Final_redhat_00001.1.el9eap, 0:1.10.0-46.Final_redhat_00044.1.el9eap, 0:2.2.40-1.SP3_redhat_00001.1.el9eap, 0:2.3.14-11.SP11_redhat_00001.1.el9eap, 0:2.5.5-24.SP12_redhat_00016.1.el9eap, 0:2.5.5-30.SP12_redhat_00020.1.el9eap, 0:2.16.0-22.redhat_00057.1.el9eap, 0:2.18.8-1.redhat_00003.1.el9eap, 0:4.1.135-1.Final_redhat_00001.1.el9eap, 0:5.0.31-3.SP2_redhat_00001.1.el9eap, 0:7.4.25-2.GA_redhat_00001.1.el9eap
  • Red Hat Red Hat JBoss Enterprise Application Platform 8.1.7.GA 4.1.135.Final-redhat-00001
  • Red Hat Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 10 0:4.1.135-1.Final_redhat_00001.1.el10eap, 0:8.1.7.1-1.GA_redhat_00004.1.el10eap, 0:801.7.1-1.GA_redhat_00001.1.el10eap
  • Red Hat Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8 0:0.9.6-2.redhat_00002.1.el8eap, 0:4.1.135-1.Final_redhat_00001.1.el8eap, 0:8.1.7.1-1.GA_redhat_00004.1.el8eap, 0:801.7.1-1.GA_redhat_00001.1.el8eap
  • Red Hat Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9 0:0.9.6-2.redhat_00002.1.el9eap, 0:4.1.135-1.Final_redhat_00001.1.el9eap, 0:8.1.7.1-1.GA_redhat_00004.1.el9eap, 0:801.7.1-1.GA_redhat_00001.1.el9eap
  • Red Hat Red Hat OpenShift AI 2.25 1788198681
  • Red Hat Red Hat OpenShift Dev Spaces 3.28 1780694994, 1780696380, 1780948325
  • Red Hat Red Hat OpenShift Dev Spaces 3.29 1782989027
  • netty Ubuntu Pro 20.04 LTS 1:4.1.45-1ubuntu0.1~esm6
  • netty Ubuntu Pro 22.04 LTS 1:4.1.48-4+deb11u2ubuntu0.1+esm3
  • netty Ubuntu Pro 24.04 LTS 1:4.1.48-9ubuntu0.1+esm3
  • netty Ubuntu Pro 26.04 LTS 1:4.1.48-16ubuntu0.1~esm2

ubuntu advisories UBUNTU-CVE-2026-42579

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • rh-sso7-keycloak red hat single sign on 7.6 18.0.20-1.redhat_00001.1.el8sso
  • rh-sso7-keycloak-server red hat single sign on 7.6 18.0.20-1.redhat_00001.1.el8sso
  • rh-sso7-keycloak red hat single sign on 7.6 18.0.20-1.redhat_00001.1.el9sso
  • rh-sso7-keycloak-server red hat single sign on 7.6 18.0.20-1.redhat_00001.1.el9sso
  • rh-sso7-keycloak red hat single sign on 7.6 18.0.20-1.redhat_00001.1.el7sso
  • rh-sso7-keycloak-server red hat single sign on 7.6 18.0.20-1.redhat_00001.1.el7sso
  • eap8-netty jboss enterprise application platform 8.1 4.1.135-1.Final_redhat_00001.1.el10eap
  • eap8-netty jboss enterprise application platform 8.1 4.1.135-1.Final_redhat_00001.1.el8eap

red hat advisories RHSA-2026:76129RHSA-2026:76130RHSA-2026:76128RHSA-2026:53645RHSA-2026:53646RHSA-2026:53644

  • netty-tcnative SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 2.0.77-150200.3.39.1
  • netty SLE Module for Package Hub 15 SP7 4.1.133-150200.4.46.1

suse advisories SUSE-SU-2026:2308-1

  • netty openSUSE Tumbleweed 4.1.133-1.1

opensuse advisories openSUSE-SU-2026:10795-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-42579 updated cvss 7.5

netty: Netty: High integrity impact due to improper DNS domain name constraint enforcement

  • Red Hat OpenShift Serverless openshift-serverless-1/kn-ekb-receiver-rhel9, openshift-serverless-1/kn-ekb-dispatcher-rhel9, openshift-serverless-1/kn-eventing-integrations-log-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-s3-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-sns-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-sqs-sink-rhel9, +4 more
    affected: workaround, no fix available
  • Red Hat build of Apicurio Registry 2 netty-codec-dns Red Hat build of Debezium 3 netty-codec-dns
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Build of Keycloak netty-codec-dns, rhbk-openshift-rhel9, rhbk/keycloak-rhel9-operator
    affected: workaround, no fix available, no fix planned “Will not fix”
  • Red Hat build of OptaPlanner 8 netty-codec-dns
    affected: workaround, no fix available
  • Red Hat Data Grid 8 netty-codec-dns Red Hat Enterprise Linux AI (RHEL AI) 3 bazel7, bazel8 Red Hat Fuse 7 netty-codec-dns Red Hat JBoss Enterprise Application Platform Expansion Pack netty-codec-dns Red Hat Process Automation 7 netty-codec-dns
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Cryostat 4 on RHEL 9 cryostat/cryostat-rhel9 4.2.0-10, cryostat/jfr-datasource-rhel9 4.2.0-10, cryostat/cryostat-reports-rhel9 4.2.0-10
    fixed: vendor fix RHSA-2026:28010
  • Red Hat Middleware Containers for OpenShift rh-sso-7/sso76-openshift-rhel8 7.6-85
    fixed: vendor fix RHSA-2026:76134
  • Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16
    fixed: vendor fix RHSA-2026:37390
show 21 more
  • Red Hat build of Keycloak 26.4.13
    fixed: vendor fix RHSA-2026:30049
  • Red Hat build of Quarkus 3.27.4.redhat netty-codec-dns 4.1.133.Final-redhat-00002
    fixed: vendor fix RHSA-2026:23808
  • Red Hat build of Quarkus 3.33.2.redhat netty-codec-dns 4.1.133.Final-redhat-00002
    fixed: vendor fix RHSA-2026:24502
  • Red Hat JBoss EAP 7.4 ELS for RHEL 7 Server eap7-wildfly 7.4.25-2.GA_redhat_00001.1.el7eap, eap7-jackson-core 2.18.8-1.redhat_00003.1.el7eap, eap7-netty 4.1.135-1.Final_redhat_00001.1.el7eap, eap7-undertow 2.2.40-2.SP3_redhat_00001.1.el7eap, eap7-jackson-databind 2.18.8-1.redhat_00003.1.el7eap, eap7-netty-all 4.1.135-1.Final_redhat_00001.1.el7eap, +78 more
    fixed: vendor fix RHSA-2026:53644
  • Red Hat JBoss EAP 8.1 for RHEL 8 eap8-jose4j 0.9.6-2.redhat_00002.1.el8eap, eap8-wildfly 8.1.7.1-1.GA_redhat_00004.1.el8eap, eap8-netty 4.1.135-1.Final_redhat_00001.1.el8eap, eap8-netty-codec 4.1.135-1.Final_redhat_00001.1.el8eap, eap8-netty-buffer 4.1.135-1.Final_redhat_00001.1.el8eap, eap8-netty-common 4.1.135-1.Final_redhat_00001.1.el8eap, +16 more Red Hat JBoss EAP 8.1 for RHEL 9 eap8-jose4j 0.9.6-2.redhat_00002.1.el9eap, eap8-wildfly 8.1.7.1-1.GA_redhat_00004.1.el9eap, eap8-netty 4.1.135-1.Final_redhat_00001.1.el9eap, eap8-netty-codec 4.1.135-1.Final_redhat_00001.1.el9eap, eap8-netty-buffer 4.1.135-1.Final_redhat_00001.1.el9eap, eap8-netty-common 4.1.135-1.Final_redhat_00001.1.el9eap, +16 more Red Hat JBoss EAP 8.1 for RHEL 10 eap8-wildfly 8.1.7.1-1.GA_redhat_00004.1.el10eap, eap8-netty 4.1.135-1.Final_redhat_00001.1.el10eap, eap8-netty-codec 4.1.135-1.Final_redhat_00001.1.el10eap, eap8-netty-buffer 4.1.135-1.Final_redhat_00001.1.el10eap, eap8-netty-common 4.1.135-1.Final_redhat_00001.1.el10eap, eap8-wildfly-modules 8.1.7.1-1.GA_redhat_00004.1.el10eap, +14 more
    fixed: vendor fix RHSA-2026:49700
  • Red Hat JBoss Enterprise Application Platform 7.4.25
    fixed: vendor fix RHSA-2026:53806
  • Red Hat JBoss Enterprise Application Platform 8.1.7.GA netty-codec-dns 4.1.135.Final-redhat-00001
    fixed: vendor fix RHSA-2026:49701
  • Red Hat OpenShift AI 2.25 rhoai/odh-trustyai-service-rhel9 1788198681
    fixed: vendor fix RHSA-2026:65126
  • Red Hat OpenShift AI 3.4 rhoai/odh-trustyai-service-rhel9 1791792525
    fixed: vendor fix RHSA-2026:84734
  • Red Hat OpenShift Dev Spaces 3.28 devspaces/server-rhel9 1780694994, devspaces/openvsx-rhel9 1780948325, devspaces/pluginregistry-rhel9 1780696380
    fixed: vendor fix RHSA-2026:25123
  • Red Hat OpenShift Dev Spaces 3.29 devspaces/multicluster-redirector-rhel9 1782989027
    fixed: vendor fix RHSA-2026:36820
  • Red Hat Single Sign-On 7.6 for RHEL 7 Server rh-sso7-keycloak 18.0.20-1.redhat_00001.1.el7sso, rh-sso7-keycloak-server 18.0.20-1.redhat_00001.1.el7sso
    fixed: vendor fix RHSA-2026:76128
  • Red Hat Single Sign-On 7.6 for RHEL 8 rh-sso7-keycloak 18.0.20-1.redhat_00001.1.el8sso, rh-sso7-keycloak-server 18.0.20-1.redhat_00001.1.el8sso
    fixed: vendor fix RHSA-2026:76129
  • Red Hat Single Sign-On 7.6 for RHEL 9 rh-sso7-keycloak 18.0.20-1.redhat_00001.1.el9sso, rh-sso7-keycloak-server 18.0.20-1.redhat_00001.1.el9sso
    fixed: vendor fix RHSA-2026:76130
  • Red Hat Single Sign-On 7.6.13
    fixed: vendor fix RHSA-2026:76132
  • Red Hat Streams for Apache Kafka 3.2.1
    fixed: vendor fix RHSA-2026:54435
  • Red Hat Cryostat 4 on RHEL 9 cryostat/cryostat-db-rhel9 4.2.0-16, cryostat/cryostat-storage-rhel9 4.2.0-16, cryostat/cryostat-operator-bundle 4.2.0-8, cryostat/cryostat-rhel9-operator 4.2.0-15, cryostat/cryostat-agent-init-rhel9 0.7.0-8, cryostat/cryostat-grafana-dashboard-rhel9 4.2.0-10, +1 more
    not affected: vulnerable code not present
  • Red Hat build of Apache Camel 4 for Quarkus 3 netty-codec-dns
    not affected: inline mitigations already exist
  • Red Hat build of Apicurio Registry 3 netty-codec-dns Red Hat Build of Keycloak rhbk-rhel9-operator, rhbk/keycloak-rhel9 Red Hat build of Quarkus 3.27.4.redhat jna 5.8.0, db2 1.21.4, h2 2.3.230, y18n 5.0.8, cliui 8.0.1, guice 5.1.0, +1008 more Red Hat build of Quarkus 3.33.2.redhat jna 5.8.0, bson 5.6.4, h2 2.4.240, y18n 5.0.8, cliui 8.0.1, guice 5.1.0, +1017 more Red Hat JBoss Enterprise Application Platform 8.1.7.GA pom.xml, aesh 2.4, c3 0.6.4, d3 7.4.3, he 1.2.0, lr 1.4.2, +1866 more
    not affected: vulnerable code not present
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-spark-operator-rhel9, rhoai/odh-trustyai-service-rhel8, rhoai/odh-th06-cpu-torch210-py312-rhel9, rhoai/odh-th06-cpu-torch291-py312-rhel9, rhoai/odh-th06-rocm64-torch291-py312-rhel9, rhoai/odh-th06-cuda130-torch210-py312-rhel9, +1 more
    not affected: vulnerable code not in execute path
  • Red Hat OpenShift AI 2.25 rhoai/odh-rhel9-operator 1788331391, rhoai/odh-vllm-cpu-rhel9 1786712073, rhoai/odh-dashboard-rhel9 1788312226, rhoai/odh-modelmesh-rhel9 1788319539, rhoai/odh-operator-bundle 1788332816, rhoai/odh-vllm-cuda-rhel9 1786710989, +70 more
    not affected: vulnerable code not present

4 more not affected in the full advisory

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

1.01% chance of exploitation in the next 30 days, higher than 63% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/netty/netty/security/advisories/GHSA-cm33-6792-r9fm referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
maven io.netty:netty-codec-dns
>=4.2.0.Alpha1, <4.2.13.Final
<4.1.133.Final
4.2.13.Final
4.1.133.Final

Affected products

  • netty netty
  • Red Hat Cryostat 4 on RHEL 9
  • Red Hat Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16
  • Red Hat Red Hat build of Quarkus 3.27.4
  • Red Hat Red Hat build of Quarkus 3.33.2
  • Red Hat Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7
  • Red Hat Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8
  • Red Hat Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 9
  • Red Hat Red Hat JBoss Enterprise Application Platform 8.1.7.GA
  • Red Hat Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 10
  • Red Hat Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
  • Red Hat Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
  • Red Hat Streams for Apache Kafka 3.2.1
  • Red Hat Red Hat OpenShift AI 2.25
  • Red Hat Red Hat OpenShift Dev Spaces 3.28
  • Red Hat Red Hat OpenShift Dev Spaces 3.29
  • Red Hat OpenShift Serverless
  • Red Hat Red Hat build of Apache Camel 4 for Quarkus 3
  • Red Hat Red Hat build of Apicurio Registry 2
  • Red Hat Red Hat build of Apicurio Registry 3
  • Red Hat Red Hat build of Debezium 3
  • Red Hat Red Hat Build of Keycloak
  • Red Hat Red Hat build of OptaPlanner 8
  • Red Hat Red Hat Data Grid 8
  • Red Hat Red Hat Enterprise Linux AI (RHEL AI) 3
  • Red Hat Red Hat Fuse 7
  • Red Hat Red Hat JBoss Enterprise Application Platform Expansion Pack
  • Red Hat Red Hat OpenShift AI (RHOAI)
  • Red Hat Red Hat Process Automation 7
  • Red Hat Red Hat Single Sign-On 7
  • Red Hat streams for Apache Kafka 2

Classification

Weakness
  • CWE-20 Improper Input Validation
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-626 Null Byte Interaction Error (Poison Null Byte)
  • CWE-1286 Improper Validation of Syntactic Correctness of Input
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.