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Fencer Intel
medium 6.5

CVE-2026-42585 json

Netty: HTTP Request Smuggling due to malformed Transfer-Encoding

published 6mo ago modified 14d ago also EUVD-2026-30128 , GHSA-38f8-5428-x5cv

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 18%
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 incorrectly parses malformed Transfer-Encoding, enabling request smuggling attacks. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

Patch / fix

  • maven io.netty:netty-codec-http 4.1.133.Final, 4.2.13.Final
  • netty netty 4.1.133.Final, 4.2.13.Final
  • io.netty netty-codec-http 4.1.133.Final, 4.2.13.Final
  • netty Ubuntu Pro 14.04 LTS 1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1
  • netty Ubuntu Pro 16.04 LTS 1:4.0.34-1ubuntu0.1~esm4
  • netty Ubuntu Pro 18.04 LTS 1:4.1.7-4ubuntu0.1+esm6
  • 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-2026-42585

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

  • 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
  • eap8-netty jboss enterprise application platform 8.1 4.1.135-1.Final_redhat_00001.1.el9eap
  • eap8-jose4j jboss enterprise application platform 8.1 0.9.6-2.redhat_00002.1.el8eap
  • eap8-jose4j jboss enterprise application platform 8.1 0.9.6-2.redhat_00002.1.el9eap
  • eap8-wildfly jboss enterprise application platform 8.1 8.1.7.1-1.GA_redhat_00004.1.el10eap
  • eap8-wildfly jboss enterprise application platform 8.1 8.1.7.1-1.GA_redhat_00004.1.el8eap
  • eap8-wildfly jboss enterprise application platform 8.1 8.1.7.1-1.GA_redhat_00004.1.el9eap

red hat advisories RHSA-2026:73976RHSA-2026:73644RHSA-2026:53645RHSA-2026:53646RHSA-2026:53644RHSA-2026:49700

  • 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-2026-42585 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.

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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-2026-42585 updated cvss 6.5

netty: io.netty/netty-codec-http: Netty: Request smuggling via malformed Transfer-Encoding parsing

  • Red Hat Cryostat 4 netty-codec-http 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 AMQ Broker 7 netty-codec-http Red Hat AMQ Clients netty-codec-http Red Hat build of Apache Camel 4 for Quarkus 3 netty-codec-http Red Hat build of Apache Camel for Spring Boot 4 netty-codec-http
    +15 more products
    Red Hat build of Apicurio Registry 2 netty-codec-http Red Hat build of Apicurio Registry 3 netty-codec-http Red Hat build of Debezium 3 netty-codec-http Red Hat Build of Keycloak netty-codec-http, rhbk-rhel9-operator, rhbk/keycloak-rhel9, rhbk-openshift-rhel9, rhbk/keycloak-rhel9-operator Red Hat build of OptaPlanner 8 netty-codec-http Red Hat build of Quarkus netty-codec-http Red Hat Data Grid 8 netty-codec-http Red Hat Fuse 7 netty-codec-http Red Hat JBoss Enterprise Application Platform Expansion Pack netty-codec-http Red Hat OpenShift AI (RHOAI) rhoai/odh-modelmesh-rhel8, rhoai/odh-modelmesh-rhel9, rhoai/odh-spark-operator-rhel9, rhoai/odh-trustyai-service-rhel8, rhoai/odh-trustyai-service-rhel9, rhoai/odh-th06-cpu-torch210-py312-rhel9, +4 more Red Hat OpenShift Dev Spaces devspaces/server-rhel9, devspaces/openvsx-rhel9, devspaces/pluginregistry-rhel9, devspaces/multicluster-redirector-rhel9 Red Hat Process Automation 7 netty-codec-http Red Hat Single Sign-On 7 netty-codec-http Red Hat streams for Apache Kafka 2 netty-codec-http Red Hat streams for Apache Kafka 3 netty-codec-http
    affected: workaround, no fix available “Fix deferred”
  • 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 7.1 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 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-http 4.1.135.Final-redhat-00001
    fixed: vendor fix RHSA-2026:49701
  • Red Hat Enterprise Linux AI (RHEL AI) 3 bazel6, bazel7, bazel8 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 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

0.27% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/netty/netty/security/advisories/GHSA-38f8-5428-x5cv referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD 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-http
>=4.2.0.Alpha1, <4.2.13.Final
<4.1.133.Final
4.2.13.Final
4.1.133.Final

Affected products

  • netty netty
  • io.netty netty-codec-http

Classification

Weakness
  • CWE-444 Inconsistent Interpretation of HTTP Requests

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.