CVE-2026-45416

About vulnerability

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.

Affected product:

Apache CXF , Apache Hadoop , Apache Kafka , Apache Log4j , Apache Solr , Apache Spark , Eclipse Jetty , Netty , React , Spring , Wildfly , artemis , async-http-client , avro , aws-sdk-java , azure-sdk-for-java , bolt-connection-java , californium , camel , cassandra-java-driver , catalyst , couchbase-jvm-clients , curator , docker-java , drill , elasticsearch , flink , flink-shaded , grpc-java , infinispan , java-driver , lettuce , logging-flume , milo , neo4j-java-driver , neo4j-ogm , netty , olingo-odata4 , pgjdbc-ng , pulsar , rabbitmq-stream-java-client , rsocket-java , stack-core , tika , vert.x , wildfly , zendesk-java-client , zookeeper

Affected packages:

avro-ipc-netty @ 1.11.0 (+7865 more)

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.