Netty <4.1.135 / <4.2.15 TLS ClientHello Buffer Overflow
CVE-2026-45416 Published on June 12, 2026

Netty: SNI handler pre-allocates up to 16 MiB from nine attacker bytes
Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, SslClientHelloHandler.decode() reads the 24-bit TLS handshake length and, when the ClientHello does not fit in the first record, eagerly allocates `ctx.alloc().buffer(handshakeLength)` (line 161). The guard at line 140 is `handshakeLength > maxClientHelloLength && maxClientHelloLength != 0`, and the commonly-used SniHandler/AbstractSniHandler constructors (SniHandler(Mapping), SniHandler(AsyncMapping), AbstractSniHandler()) pass maxClientHelloLength=0 and handshakeTimeoutMillis=0, so the length guard is disabled and no timeout is scheduled. A 16 MiB request exceeds the default pooled chunk size and becomes a huge/unpooled allocation performed immediately. The buffer is retained in the handler until the channel closes. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

NVD

Vulnerability Analysis

CVE-2026-45416 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Weakness Type

Allocation of Resources Without Limits or Throttling

The software allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.


Products Associated with CVE-2026-45416

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-45416 are published in these products:

Netty
 
Red Hat Apache Camel Quarkus
 
Red Hat Offline Knowledge Portal
 
Red Hat Quarkus
 
Red Hat Cryostat
 
Red Hat Serverless
 
Red Hat Amq Broker
 
Red Hat Amq Clients
 
Red Hat Apache Camel Hawtio
 
Red Hat Camel Quarkus
 
Red Hat Camel Spring Boot
 
Red Hat Apicurio Registry
 
Red Hat Debezium
 
Red Hat Build Keycloak
 
Red Hat Jboss Data Grid
 
Red Hat Jboss Fuse
 
Red Hat Jboss Enterprise Application Platform
 
Red Hat Jbosseapxp
 
Red Hat Openshift Ai
 
Red Hat Openshift Devspaces
 
Red Hat Amq Streams
 
Red Hat Enterprise Linux Ai
 
Red Hat Satellite
 
Red Hat Single Sign On
 
Red Hat Kafka
 
Red Hat Apache Camel Spring Boot
 

Affected Versions

netty: Red Hat Build of Apache Camel 3.33 for Quarkus 3.33.2.SP1: Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16: Red Hat build of Quarkus 3.27.4.SP1: Red Hat build of Quarkus 3.33.2.SP1: Red Hat Data Grid 8.6.2: Red Hat Streams for Apache Kafka 2.9.4: Red Hat Offline Knowledge Portal 1.2.9: Red Hat Cryostat 4: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat AMQ Broker 7: Red Hat AMQ Clients: Red Hat build of Apache Camel 4 for Quarkus 3: Red Hat build of Apache Camel - HawtIO 4: Red Hat build of Apicurio Registry 3: Red Hat build of Debezium 3: Red Hat Build of Keycloak: Red Hat Build of Keycloak: Red Hat Build of Keycloak: Red Hat Build of Keycloak: Red Hat Build of Keycloak: Red Hat Enterprise Linux AI (RHEL AI) 3: Red Hat Enterprise Linux AI (RHEL AI) 3: Red Hat Enterprise Linux AI (RHEL AI) 3: Red Hat Fuse 7: Red Hat JBoss Enterprise Application Platform 7: Red Hat JBoss Enterprise Application Platform 8: Red Hat JBoss Enterprise Application Platform Expansion Pack: Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat OpenShift Dev Spaces: Red Hat OpenShift Dev Spaces: Red Hat OpenShift Dev Spaces: Red Hat OpenShift Dev Spaces: Red Hat OpenShift Dev Spaces: Red Hat Satellite 6: Red Hat Satellite 6: Red Hat Single Sign-On 7: Red Hat streams for Apache Kafka 3:

Exploit Probability

EPSS
0.48%
Percentile
38.63%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.