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Fencer Vulns
high 7.5

CVE-2026-62243 json

Netty 4.2.0 through 4.2.16 TLS Hostname Verification Bypass

published 2026-08-22 2 mo ago modified 2026-10-14 25 d ago also EUVD-2026-64271

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

Netty (io.netty:netty-handler) versions from 4.2.0.Final through 4.2.16.Final and versions through 4.1.136.Final disable TLS hostname verification on the SslProvider.OPENSSL client path when a plain (non-extended) X509TrustManager is used and Unsafe-based trust-manager wrapping is unavailable (Java 25+). In this configuration the OpenSSL client does not perform hostname verification, allowing a man-in-the-middle attacker to present a certificate issued for a different hostname that is accepted without validation. Fixed in 4.2.17.Final and 4.1.137.Final.

Patch / fix

  • netty netty 4.1.137.Final, 4.2.16.Final
  • eap8-jaxb jboss enterprise application platform 8.1 4.0.7-4.redhat_00001.1.el10eap
  • eap8-txw2 jboss enterprise application platform 8.1 4.0.7-4.redhat_00001.1.el10eap
  • eap8-xsom jboss enterprise application platform 8.1 4.0.7-4.redhat_00001.1.el10eap
  • eap8-log4j jboss enterprise application platform 8.1 2.25.4-1.redhat_00003.1.el10eap
  • eap8-netty jboss enterprise application platform 8.1 4.1.136-1.Final_redhat_00001.1.el10eap
  • eap8-rngom jboss enterprise application platform 8.1 4.0.7-4.redhat_00001.1.el10eap
  • eap8-slf4j jboss enterprise application platform 8.1 2.0.18-1.redhat_00001.1.el10eap
  • eap8-neethi jboss enterprise application platform 8.1 3.2.2-1.redhat_00001.1.el10eap

red hat advisories RHSA-2026:70230RHSA-2026:70229RHSA-2026:70228

  • netty-tcnative SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 2.0.84-150200.3.51.1
  • netty SLE Module for Package Hub 15 SP7 4.1.138-150200.4.56.1

suse advisories SUSE-SU-2026:4391-1

  • netty openSUSE Tumbleweed 4.1.138-1.1

opensuse advisories openSUSE-SU-2026:11882-1

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-2026-62243 updated cvss 7.5

io.netty/netty-handler: Netty: TLS hostname verification bypass via OpenSSL client path misconfiguration

  • Red Hat Exploit Intelligence exploit-intelligence/agent-client-rhel9 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 4 for Quarkus 3 netty-handler 4.1.136.Final-redhat-00001 Red Hat build of Apicurio Registry 3 netty-handler 4.1.136.Final-redhat-00001
    affected: workaround, no fix available
  • Red Hat Ceph Storage 6 ceph, cephadm, librbd1, librgw2, rbd-nbd, ceph-mib, +16 more Red Hat Ceph Storage 7 ceph, cephadm, librbd1, librgw2, rbd-nbd, ceph-mib, +16 more Red Hat Ceph Storage 8 ceph, cephadm, librbd1, librgw2, rbd-nbd, ceph-mib, +17 more Red Hat Ceph Storage 9 ceph, cephadm, librbd1, librgw2, rbd-nbd, ceph-mib, +19 more
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux 10 ceph Red Hat Enterprise Linux AI (RHEL AI) 3 bazel6 6.5.0-2.el9ai, bazel7 7.7.1-1.el9ai, bazel8 8.6.0-1.el9ai
    affected: workaround, no fix available
  • Red Hat Fuse 7 netty-handler 4.1.136.Final-redhat-00001 Red Hat JBoss Enterprise Application Platform 7 netty-handler 4.1.136.Final-redhat-00001, jboss-eap-7/eap74-els-openjdk8-openshift-rhel8, jboss-eap-7/eap74-els-openjdk11-openshift-rhel8, jboss-eap-7/eap74-els-openjdk17-openshift-rhel8
    affected: workaround, no fix planned “Will not fix”
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-th06-cpu-torch291-py312-rhel9, rhoai/odh-th06-cuda130-torch291-py312-rhel9
    affected: workaround, no fix available
  • Red Hat Single Sign-On 7 netty-handler 4.1.136.Final-redhat-00001
    affected: workaround, no fix planned “Will not fix”
  • Red Hat AMQ Broker 7.13.6
    fixed: vendor fix RHSA-2026:66545
  • Red Hat AMQ Broker 7.14.1
    fixed: vendor fix RHSA-2026:66488
show 21 more
  • Red Hat Build of Apache Camel 3.33.3.SP1 netty-handler 4.1.137.Final-redhat-00001
    fixed: vendor fix RHSA-2026:63302
  • Red Hat build of Apache Camel 4.18.4 for Spring Boot 3.5.16
    fixed: vendor fix RHSA-2026:71675
  • Red Hat Build of Debezium 3.6
    fixed: vendor fix RHSA-2026:83612
  • Red Hat build of Keycloak 26.4 rhbk/keycloak-rhel9 26.4-26, rhbk/keycloak-rhel9-operator 26.4-26, rhbk/keycloak-operator-bundle 26.4.16-2
    fixed: vendor fix RHSA-2026:68276
  • Red Hat build of Keycloak 26.4.16
    fixed: vendor fix RHSA-2026:68280
  • Red Hat build of Keycloak 26.6 rhbk/keycloak-rhel9 26.6-20, rhbk/keycloak-rhel9-operator 26.6-20, rhbk/keycloak-operator-bundle 26.6.7-3
    fixed: vendor fix RHSA-2026:68277
  • Red Hat build of Keycloak 26.6.7
    fixed: vendor fix RHSA-2026:68278
  • Red Hat build of Quarkus 3.27.5.SP1 netty-handler 4.1.137.Final-redhat-00001
    fixed: vendor fix RHSA-2026:62515
  • Red Hat build of Quarkus 3.33.3.SP1 netty-handler 4.1.137.Final-redhat-00001
    fixed: vendor fix RHSA-2026:62555
  • Red Hat Data Grid 8.6.3
    fixed: vendor fix RHSA-2026:69296
  • Red Hat JBoss EAP 8.1 for RHEL 8 eap8-jaxb 4.0.7-4.redhat_00001.1.el8eap, eap8-txw2 4.0.7-4.redhat_00001.1.el8eap, eap8-xsom 4.0.7-4.redhat_00001.1.el8eap, eap8-rngom 4.0.7-4.redhat_00001.1.el8eap, eap8-log4j 2.25.4-1.redhat_00003.1.el8eap, eap8-neethi 3.2.2-1.redhat_00001.1.el8eap, +101 more
    fixed: vendor fix RHSA-2026:70228
  • Red Hat JBoss EAP 8.1 for RHEL 9 eap8-jaxb 4.0.7-4.redhat_00001.1.el9eap, eap8-txw2 4.0.7-4.redhat_00001.1.el9eap, eap8-xsom 4.0.7-4.redhat_00001.1.el9eap, eap8-rngom 4.0.7-4.redhat_00001.1.el9eap, eap8-log4j 2.25.4-1.redhat_00003.1.el9eap, eap8-neethi 3.2.2-1.redhat_00001.1.el9eap, +101 more
    fixed: vendor fix RHSA-2026:70229
  • Red Hat JBoss EAP 8.1 for RHEL 10 eap8-jaxb 4.0.7-4.redhat_00001.1.el10eap, eap8-txw2 4.0.7-4.redhat_00001.1.el10eap, eap8-xsom 4.0.7-4.redhat_00001.1.el10eap, eap8-rngom 4.0.7-4.redhat_00001.1.el10eap, eap8-log4j 2.25.4-1.redhat_00003.1.el10eap, eap8-neethi 3.2.2-1.redhat_00001.1.el10eap, +100 more
    fixed: vendor fix RHSA-2026:70230
  • Red Hat JBoss Enterprise Application Platform 8.1.8.GA netty-handler 4.1.136.Final-redhat-00001
    fixed: vendor fix RHSA-2026:70277
  • Red Hat OpenShift AI 2.25 rhoai/odh-modelmesh-rhel9 1790881700, rhoai/odh-trustyai-service-rhel9 1790933094
    fixed: vendor fix RHSA-2026:87410
  • Red Hat OpenShift AI 3.4 rhoai/odh-spark-operator-rhel9 1790958993, rhoai/odh-trustyai-service-rhel9 1791792525, rhoai/odh-th06-cpu-torch210-py312-rhel9 1791874335, rhoai/odh-th06-rocm64-torch291-py312-rhel9 1791872119, rhoai/odh-th06-cuda130-torch210-py312-rhel9 1791961113
    fixed: vendor fix RHSA-2026:84734
  • Red Hat OpenShift AI 3.5 rhoai/odh-trustyai-service-rhel9 1791951741
    fixed: vendor fix RHSA-2026:86891
  • Red Hat OpenShift Dev Spaces 3.31 devspaces/server-rhel9 1792775639, devspaces/openvsx-rhel9 1792494821, devspaces/jetbrains-ide-rhel9 1792476427, devspaces/pluginregistry-rhel9 1792495212, devspaces/multicluster-redirector-rhel9 1792491532
    fixed: vendor fix RHSA-2026:90321
  • Red Hat Build of Apache Camel 3.33.3.SP1 jimfs 1.1, jna 5.8.0, bcel 6.7.0, gax 2.74.1, icu4j 78.2, joni 2.2.6, +1618 more Red Hat build of Quarkus 3.27.5.SP1 jna 5.8.0, db2 1.21.4, h2 2.3.230, y18n 5.0.8, cliui 8.0.1, guice 5.1.0, +1009 more Red Hat build of Quarkus 3.33.3.SP1 jna 5.8.0, h2 2.4.240, y18n 5.0.8, cliui 8.0.1, guice 5.1.0, wasm 2.15.3, +1018 more Red Hat JBoss Enterprise Application Platform 8.1.8.GA pom.xml, aesh 2.4, c3 0.6.4, d3 7.4.3, he 1.2.0, lr 1.4.2, +1868 more
    not affected: vulnerable code not present
  • Red Hat JBoss Enterprise Application Platform Expansion Pack netty-handler 4.1.136.Final-redhat-00001
    not affected: component not present
  • Red Hat Offline Knowledge Portal offline-knowledge-portal/rhokp-rhel9
    not affected: vulnerable code not in execute path

6 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
none
Automatable
yes
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • netty netty

Classification

Weakness
  • CWE-297 Improper Validation of Certificate with Host Mismatch

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.