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Fencer Intel
high 7.5

CVE-2026-42583 json

Netty: Lz4FrameDecoder resource exhaustion

published 6mo ago modified 14d ago also EUVD-2026-30126 , GHSA-mj4r-2hfc-f8p6

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 40%
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, Lz4FrameDecoder allocates a ByteBuf of size decompressedLength (up to 32 MB per block) before LZ4 runs. A peer only needs a 21-byte header plus compressedLength payload bytes - 22 bytes if compressedLength == 1 - to force that allocation. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

Patch / fix

  • maven io.netty:netty-codec-compression 4.2.13.Final
  • maven io.netty:netty-codec 4.1.133.Final
  • netty netty 4.1.133.Final, 4.2.13.Final
  • io.netty netty-codec 4.1.133.Final
  • io.netty netty-codec-compression 4.2.13.Final
  • eap7-netty jboss enterprise application platform eus 7.1 4.1.63-4.Final_redhat_00005.1.ep7.el7
  • eap7-wildfly jboss enterprise application platform eus 7.1 7.1.16-1.GA_redhat_00002.1.ep7.el7
  • eap7-hibernate jboss enterprise application platform eus 7.1 5.1.17-5.Final_redhat_00006.1.ep7.el7
  • eap7-netty-all jboss enterprise application platform eus 7.1 4.1.63-4.Final_redhat_00005.1.ep7.el7
  • eap7-hibernate-core jboss enterprise application platform eus 7.1 5.1.17-5.Final_redhat_00006.1.ep7.el7
  • eap7-hibernate-java8 jboss enterprise application platform eus 7.1 5.1.17-5.Final_redhat_00006.1.ep7.el7
  • eap7-wildfly-modules jboss enterprise application platform eus 7.1 7.1.16-1.GA_redhat_00002.1.ep7.el7
  • eap7-hibernate-envers jboss enterprise application platform eus 7.1 5.1.17-5.Final_redhat_00006.1.ep7.el7

red hat advisories RHSA-2026:73976RHSA-2026:73644

  • 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

Is CVE-2026-42583 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

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-2026-42583 updated cvss 7.5

netty: io.netty/netty-codec-compression: io.netty/netty-codec: Netty: Denial of Service via excessive memory allocation in LZ4FrameDecoder

  • 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 Red Hat build of Apache Camel - HawtIO 4 netty-codec-compression
    affected: workaround, no fix available
  • Red Hat build of Apicurio Registry 2 netty-codec
    affected: workaround, no fix planned “Will not fix”
  • Red Hat build of Apicurio Registry 3 netty-codec
    affected: workaround, no fix available
  • Red Hat build of Debezium 3 netty-codec
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Build of Keycloak rhbk-rhel9-operator, rhbk/keycloak-rhel9, 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
    affected: workaround, no fix available
  • Red Hat Fuse 7 netty-codec
    affected: workaround, no fix planned “Will not fix”
  • Red Hat JBoss Enterprise Application Platform 8 netty-codec
    affected: workaround, no fix available
show 21 more
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-modelmesh-rhel9, rhoai/odh-openvino-model-server-rhel9
    affected: workaround, no fix available, no fix planned “Will not fix”
  • Red Hat OpenShift Dev Spaces devspaces/server-rhel9, devspaces/openvsx-rhel9, devspaces/pluginregistry-rhel9
    affected: workaround, no fix available
  • Red Hat Process Automation 7 netty-codec Red Hat Single Sign-On 7 netty-codec
    affected: workaround, no fix planned “Will not fix”
  • Red Hat streams for Apache Kafka 2 netty-codec
    affected: workaround, no fix available
  • Red Hat AMQ Clients 2026.Q3
    fixed: vendor fix RHSA-2026:69459
  • Red Hat AMQ Broker 7.14.1
    fixed: vendor fix RHSA-2026:66488
  • Red Hat build of Keycloak 26.4.13
    fixed: vendor fix RHSA-2026:30049
  • Red Hat Data Grid 8.6.2
    fixed: vendor fix RHSA-2026:41951
  • Red Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7 Server eap7-wildfly 7.1.16-1.GA_redhat_00002.1.ep7.el7, eap7-netty 4.1.63-4.Final_redhat_00005.1.ep7.el7, eap7-hibernate 5.1.17-5.Final_redhat_00006.1.ep7.el7, eap7-netty-all 4.1.63-4.Final_redhat_00005.1.ep7.el7, eap7-wildfly-modules 7.1.16-1.GA_redhat_00002.1.ep7.el7, eap7-hibernate-core 5.1.17-5.Final_redhat_00006.1.ep7.el7, +4 more
    fixed: vendor fix RHSA-2026:73976
  • Red Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7 Server eap7-wildfly 7.3.19-1.GA_redhat_00004.1.el7eap, eap7-netty 4.1.63-7.Final_redhat_00005.1.el7eap, eap7-hibernate 5.3.39-1.Final_redhat_00001.1.el7eap, eap7-netty-all 4.1.63-7.Final_redhat_00005.1.el7eap, eap7-wildfly-modules 7.3.19-1.GA_redhat_00004.1.el7eap, eap7-wildfly-javadocs 7.3.19-1.GA_redhat_00004.1.el7eap, +28 more
    fixed: vendor fix RHSA-2026:73644
  • 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 3.29 devspaces/multicluster-redirector-rhel9 1782989027
    fixed: vendor fix RHSA-2026:36820
  • Red Hat Streams for Apache Kafka 2.9.4
    fixed: vendor fix RHSA-2026:34608
  • Red Hat Streams for Apache Kafka 3.2.1
    fixed: vendor fix RHSA-2026:54435
  • Red Hat Cryostat 4 netty-codec
    not affected: vulnerable code not present
  • Red Hat build of Apache Camel 4 for Quarkus 3 netty-codec
    not affected: inline mitigations already exist
  • Red Hat build of Apache Camel for Spring Boot 4 netty-codec Red Hat Build of Keycloak netty-codec Red Hat build of Quarkus netty-codec Red Hat Enterprise Linux AI (RHEL AI) 3 bazel6, bazel7, bazel8
    not affected: vulnerable code not present
  • Red Hat JBoss Enterprise Application Platform 7 netty-codec Red Hat JBoss Enterprise Application Platform Expansion Pack netty-codec, netty-codec-compression
    not affected: component not present
  • Red Hat Offline Knowledge Portal offline-knowledge-portal/rhokp-rhel9
    not affected: inline mitigations already exist
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-modelmesh-rhel8, 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, +2 more 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 Red Hat OpenShift AI 3.4 rhoai/odh-cli-rhel9 1791509689, rhoai/rhai-cli-rhel9 1791509689, rhoai/odh-automl-rhel9 1791535789, rhoai/odh-mlflow-rhel9 1791865967, rhoai/odh-autorag-rhel9 1791557539, rhoai/odh-trainer-rhel9 1791869783, +99 more Red Hat OpenShift Dev Spaces 3.29 devspaces/udi-rhel9 1782991491, devspaces/code-rhel9 1782498475, devspaces/server-rhel9 1783033397, devspaces/openvsx-rhel9 1783007534, devspaces/traefik-rhel9 1782403274, devspaces/udi-base-rhel9 1782987705, +10 more Red Hat Satellite 6 candlepin, candlepin-selinux
    not affected: vulnerable code not present

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
5mo ago

Exploit prediction

0.46% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/netty/netty/security/advisories/GHSA-mj4r-2hfc-f8p6 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:N/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
maven io.netty:netty-codec-compression
<4.2.13.Final
4.2.13.Final
maven io.netty:netty-codec
<4.1.133.Final
4.1.133.Final

Affected products

  • netty netty
  • io.netty netty-codec
  • io.netty netty-codec-compression

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Intel 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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.