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TI-2023-17287 Aliases CVE-2023-34462GHSA-6mjq-h674-j845

netty-handler SniHandler 16MB allocation

Priority LOW 34CWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 13 fixed, 19 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-400.

Summary

Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. The `SniHandler` can allocate up to 16MB of heap for each channel during the TLS handshake. When the handler or the channel does not have an idle timeout, it can be used to make a TCP server using the `SniHandler` to allocate 16MB of heap. The `SniHandler` class is a handler that waits for the TLS handshake to configure a `SslHandler` according to the indicated server name by the `ClientHello` record. For this matter it allocates a `ByteBuf` using the value defined in the `ClientHello` record. Normally the value of the packet should be smaller than the handshake packet but there are not checks done here and the way the code is written, it is possible to craft a packet that makes the `SslClientHelloHandler`. This vulnerability has been fixed in version 4.1.94.Final.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.02459 84th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial netty (netty): 4.1.94.Finalio.netty:netty-handler (Maven): 4.1.94.FinalRed Hat: 13 advisoriesRed Hat: 13 fixed, 19 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
nettynettybefore 4.1.94.Final4.1.94.FinalPatch availableCNA
—io.netty:netty-handler (Maven)before 4.1.94.Final4.1.94.FinalPatch availableGHSA-6mjq-h674-j845
  • netty Vendornetty Affected before 4.1.94.Final Fixed in 4.1.94.Final Patch available CNA
  • io.netty:netty-handler (Maven) Vendor— Affected before 4.1.94.Final Fixed in 4.1.94.Final Patch available GHSA-6mjq-h674-j845

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*before 4.1.94Vulnerablenetty
  • cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* Versions before 4.1.94 Vulnerable ·netty

Remediation

  • Fix · CNA netty (netty) Fixed in 4.1.94.Final
  • Fix · GHSA-6mjq-h674-j845 io.netty:netty-handler (Maven) Fixed in 4.1.94.Final Advisory →

Red Hat 13 advisories

  • RHSA-2024:0148 Released 2024-01-10 · Red Hat rating Important
    Red Hat Integration Camel K 1.10.5 release and security update
    • RHINT Camel-K 1.10.5
  • RHSA-2023:7700 Released 2023-12-07 · Red Hat rating Important
    Red Hat build of Quarkus 2.13.9 release and security update
    • Red Hat build of Quarkus 2.13.9
  • RHSA-2023:7697 Released 2023-12-07 · Red Hat rating Moderate
    AMQ Clients 2023.Q4
    • Red Hat AMQ Clients
Show 10 more Red Hat advisories
  • RHSA-2023:7669 Released 2023-12-06 · Red Hat rating Moderate
    Red Hat build of Cryostat 2.4.0: new RHEL 8 container images
    • Cryostat 2 on RHEL 8 cryostat-tech-preview/cryostat-grafana-dashboard-rhel8, cryostat-tech-preview/cryostat-operator-bundle, cryostat-tech-preview/cryostat-reports-rhel8 +3
  • RHSA-2023:7653 Released 2023-12-05 · Red Hat rating Important
    Service Registry (container images) release and security update [2.5.4 GA]
    • RHINT Service Registry 2.5.4 GA
  • RHSA-2023:5946 Released 2023-10-19 · Red Hat rating Important
    Red Hat AMQ Broker 7.11.3 release and security update
    • Red Hat AMQ Broker 7
  • RHSA-2023:5485 Released 2023-10-06 · Red Hat rating Important
    Red Hat JBoss Enterprise Application Platform 7.4.13 security update on RHEL 8
    • Red Hat JBoss EAP 7.4 for RHEL 8 eap7-activemq-artemis-2.16.0-15.redhat_00049.1.el8eap, eap7-activemq-artemis-cli-2.16.0-15.redhat_00049.1.el8eap, eap7-activemq-artemis-commons-2.16.0-15.redhat_00049.1.el8eap +47
  • RHSA-2023:5486 Released 2023-10-06 · Red Hat rating Important
    Red Hat JBoss Enterprise Application Platform 7.4.13 security update on RHEL 9
    • Red Hat JBoss EAP 7.4 for RHEL 9 eap7-activemq-artemis-2.16.0-15.redhat_00049.1.el9eap, eap7-activemq-artemis-cli-2.16.0-15.redhat_00049.1.el9eap, eap7-activemq-artemis-commons-2.16.0-15.redhat_00049.1.el9eap +47
  • RHSA-2023:5484 Released 2023-10-05 · Red Hat rating Important
    Red Hat JBoss Enterprise Application Platform 7.4.13 security update on RHEL 7
    • Red Hat JBoss EAP 7.4 for RHEL 7 Server eap7-activemq-artemis-2.16.0-15.redhat_00049.1.el7eap, eap7-activemq-artemis-cli-2.16.0-15.redhat_00049.1.el7eap, eap7-activemq-artemis-commons-2.16.0-15.redhat_00049.1.el7eap +47
  • RHSA-2023:5488 Released 2023-10-05 · Red Hat rating Important
    Red Hat JBoss Enterprise Application Platform 7.4.13 security update
    • Red Hat JBoss Enterprise Application Platform io.netty.netty-handler-4.1.94.Final-redhat-00001.jar, org.bouncycastle.bcprov-jdk18on-1.76.0.redhat-00001.jar, org.jboss.hal.hal-console-3.3.19.Final-redhat-00001-resources.jar +2
  • RHSA-2023:5441 Released 2023-10-04 · Red Hat rating Moderate
    Red Hat Integration Camel for Spring Boot 4.0.0 release and security update
    • RHINT Camel-Springboot 4.0.0
  • RHSA-2023:5396 Released 2023-09-28 · Red Hat rating Moderate
    Red Hat Data Grid 8.4.4 security update
    • Red Hat Data Grid 8.4.4
  • RHSA-2023:5165 Released 2023-09-14 · Red Hat rating Important
    Red Hat AMQ Streams 2.5.0 release and security update
    • Red Hat AMQ Streams 2.5.0

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
A-MQ Clients 2AffectedNo fix yet
Migration Toolkit for Applications 6AffectedNo fix yet
Migration Toolkit for RuntimesAffectedNo fix yet
Red Hat A-MQ OnlineAffectedNo fix planned: Out of support scope
Red Hat Decision Manager 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 8AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux 9AffectedNo fix planned: Will not fix
Red Hat Fuse 7AffectedNo fix planned: Out of support scope
Red Hat Integration Camel Quarkus 2AffectedNo fix yet
Red Hat JBoss Data Grid 7AffectedNo fix planned: Will not fix
Red Hat JBoss Enterprise Application Platform 6AffectedNo fix planned: Out of support scope
Red Hat JBoss Enterprise Application Platform Expansion PackAffectedNo fix yet
Red Hat JBoss Fuse Service Works 6AffectedNo fix planned: Out of support scope
Red Hat OpenShift Application RuntimesAffectedNo fix planned: Out of support scope
Red Hat Process Automation 7AffectedNo fix planned: Out of support scope
Red Hat Single Sign-On 7AffectedNo fix planned: Will not fix
Red Hat build of Apache Camel for Spring Boot 3AffectedNo fix yet
Red Hat build of OptaPlanner 8AffectedNo fix yet
streams for Apache KafkaAffectedNo fix yet
Cryostat 2 on RHEL 8Fixed RHSA-2023:7669
RHINT Camel-K 1.10.5Fixed RHSA-2024:0148
RHINT Camel-Springboot 4.0.0Fixed RHSA-2023:5441
RHINT Service Registry 2.5.4 GAFixed RHSA-2023:7653
Red Hat AMQ Broker 7Fixed RHSA-2023:5946
Red Hat AMQ ClientsFixed RHSA-2023:7697
Red Hat AMQ Streams 2.5.0Fixed RHSA-2023:5165
Red Hat Data Grid 8.4.4Fixed RHSA-2023:5396
Red Hat JBoss EAP 7.4 for RHEL 7 ServerFixed RHSA-2023:5484
Red Hat JBoss EAP 7.4 for RHEL 8Fixed RHSA-2023:5485
Red Hat JBoss EAP 7.4 for RHEL 9Fixed RHSA-2023:5486
Red Hat JBoss Enterprise Application Platform Fixed RHSA-2023:5488
Red Hat build of Quarkus 2.13.9Fixed RHSA-2023:7700
Not affected: 10 products
  • Logging Subsystem for Red Hat OpenShift
  • Red Hat JBoss EAP 7.4 for RHEL 7 Server
  • Red Hat JBoss EAP 7.4 for RHEL 8
  • Red Hat JBoss EAP 7.4 for RHEL 9
  • Red Hat JBoss Enterprise Application Platform
  • Red Hat JBoss Enterprise Application Platform 8
  • Red Hat Virtualization 4
  • Red Hat build of Debezium 1
  • Red Hat build of Debezium 2
  • Red Hat support for Spring Boot

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-34462
  2. 2026-10-03 Alias added: GHSA-6mjq-h674-j845
  3. 2026-10-09 Fix available: Red Hat build of Quarkus 2.13.9 · Red Hat

References

Exploit 1

Patch 1

Advisory 1

Other 6

  • TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
  • TI-2026-30861 Netty: HTTP/1.0 TE+CL Coexistence Bypasses Smuggling Sanitization CVSS 3.1CRITICAL 9.8
  • TI-2026-30864 Netty: HttpClientCodec response desynchronization CVSS 3.1CRITICAL 9.1
  • TI-2026-30859 Netty: DNS Codec Input Validation Bypass in Netty (Encoder + Decoder) CVSS 3.1CRITICAL 9.1
  • TI-2026-40973 Netty: Missing CertificateID Validation in OCSP Response Allows Replay Attacks CVSS 3.1CRITICAL 9.1
  • TI-2026-40972 Uncontrolled resource consumption in netty CVSS 3.1HIGH 7.5
See all 92 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences