Improper Check for Unusual or Exceptional Conditions

Overview io.netty:netty-handler is a library that provides an asynchronous event-driven network application framework and tools for rapid development of maintainable high performance and high scalability protocol servers and clients. In other words, Netty is a NIO client server framework which...

CVE-2026-75596

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, the default io.netty.handler.ssl.SniHandler constructors use the pre-handshake ClientHello aggregation path in handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java at...

DEBIAN-CVE-2026-75596

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, the default io.netty.handler.ssl.SniHandler constructors use the pre-handshake ClientHello aggregation path in handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java at...

CVE-2026-75596

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, the default io.netty.handler.ssl.SniHandler constructors use the pre-handshake ClientHello aggregation path in handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java at...

UBUNTU-CVE-2026-75596

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, the default io.netty.handler.ssl.SniHandler constructors use the pre-handshake ClientHello aggregation path in handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java at...

CVE-2026-75595 Netty: SNI Routing Bypass via Fragmented TLS ClientHello Causing Fallback to Default SslContext

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Fina and 4.2.17.Final, io.netty.handler.ssl.SslClientHelloHandlerdecode checks the wrong offset before reading the four-byte TLS handshake header, so a ClientHello whose handshake header spans records can cause...

CVE-2026-75595 Netty: SNI Routing Bypass via Fragmented TLS ClientHello Causing Fallback to Default SslContext

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Fina and 4.2.17.Final, io.netty.handler.ssl.SslClientHelloHandlerdecode checks the wrong offset before reading the four-byte TLS handshake header, so a ClientHello whose handshake header spans records can cause...

CVE-2026-75595

Netty (asynchronous, event-driven network framework) is affected by an SNI routing bypass in io.netty.handler.ssl.SslClientHelloHandler#decode . The method checks the wrong offset before reading the four-byte TLS handshake header, so a ClientHello whose handshake header spans records triggers an ...

CVE-2026-75596

In Netty versions before 4.1.137.Final and 4.2.17.Final, the default SniHandler constructors trigger quadratic CPU work in SslClientHelloHandler#decode by recopying the entire handshake buffer for every additional TLS record. An unauthenticated remote attacker can fragment a large ClientHello int...

CVE-2026-75596

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, the default io.netty.handler.ssl.SniHandler constructors use the pre-handshake ClientHello aggregation path in handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java at...

CVE-2026-75596 Netty: Fragmented ClientHello records trigger quadratic pre-handshake reassembly in default SNI parsing

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, the default io.netty.handler.ssl.SniHandler constructors use the pre-handshake ClientHello aggregation path in handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java at...

CVE-2026-75596 Netty: Fragmented ClientHello records trigger quadratic pre-handshake reassembly in default SNI parsing

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, the default io.netty.handler.ssl.SniHandler constructors use the pre-handshake ClientHello aggregation path in handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java at...

CVE-2026-75596 Netty: Fragmented ClientHello records trigger quadratic pre-handshake reassembly in default SNI parsing

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, the default io.netty.handler.ssl.SniHandler constructors use the pre-handshake ClientHello aggregation path in handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java at...

PT-2026-78718

Name of the Vulnerable Software and Affected Versions Netty versions prior to 4.1.137.Final Netty versions prior to 4.2.17.Final Description An unauthenticated remote peer can cause quadratic CPU work on the event loop by advertising a large ClientHello and delivering its body in thousands of tin...

CVE-2026-75596: Inefficient Algorithmic Complexity

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, the default io.netty.handler.ssl.SniHandler constructors use the pre-handshake ClientHello aggregation path in handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java at...

SUSE CVE-2026-73214

Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.16.0, dtlsserverinputhandler and createnewconnectedudpsocket in src/apps/relay/dtlslistener.c retain OpenSSL dtls1reassemblefragment state for a 35-byte fragmented ClientHello declaring a 650,000-byte handshake before...

netty-handler: Netty: Denial of Service due to eager buffer allocation in TLS handshake

A flaw was found in Netty, a network application framework. A remote attacker can exploit this vulnerability by sending a crafted TLS Transport Layer Security ClientHello message. This can lead to an eager allocation of a large memory buffer, causing a Denial of Service DoS due to excessive memor...

CVE-2026-73214

A flaw was found in coturn. This vulnerability allows an unauthenticated remote attacker to cause a Denial of Service DoS by sending specially crafted fragmented ClientHello messages. The coturn server retains OpenSSL Datagram Transport Layer Security DTLS session state for these messages before...

JLSEC-2026-1257 Cesanta Mongoose before 7.22 contains an out-of-bounds read in the built-in TLS server function...

Cesanta Mongoose before 7.22 contains an out-of-bounds read in the built-in TLS server function mgtlsserverrecvhello, which uses an attacker-controlled sessionidlen byte from a TLS ClientHello as a buffer index without validating it against the length of received data. A remote, unauthenticated...

PT-2026-80499

Cesanta Mongoose before 7.22 contains an out-of-bounds read in the built-in TLS server function mg tls server recv hello, which uses an attacker-controlled session id len byte from a TLS ClientHello as a buffer index without validating it against the length of received data. A remote,...