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Fencer Vulns
medium 6.5

CVE-2026-42585 json

Netty: HTTP Request Smuggling due to malformed Transfer-Encoding

published 2026-05-07 6 mo ago modified 2026-10-26 13 d ago also GHSA-38f8-5428-x5cv , EUVD-2026-30128

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, 4.2.13
  • 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

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
5 mo ago

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-08).

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
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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

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 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.