CVE-2026-75596
Fixed in a distro release EPSS <1%CVSS 8.7
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 io.netty.handler.ssl.SslClientHelloHandler#decode, where handshakeBuffer.clear() and writeBytes() recopy all previously received body bytes for every additional TLS record. An unauthenticated remote peer can advertise a large ClientHello and deliver its body in thousands of tiny records, causing quadratic CPU work on the event loop before the TLS handshake completes and degrading TLS handling for other clients. This issue is fixed in versions 4.1.137.Final and 4.2.17.Final.
Products: netty
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| Maven | io.netty:netty-handler | 4.2.17.Final |
| Maven | io.netty:netty-handler | 4.1.137.Final |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Chainguard | akhq | 0.28.0-r8 |
| Chainguard | apache-camel-karavan-devmode | 4.18.1-r12 |
| Chainguard | apache-hop | 2.19.0-r3 |
| Chainguard | apache-nifi-2.11 | 2.11.0-r7 |
| Chainguard | cassandra-5.0 | 5.0.9-r7 |
| Chainguard | cassandra-fips-5.0 | 5.0.8-r14 |
| Chainguard | cassandra-reaper | 5.0.1-r1 |
| Chainguard | celeborn-0.5 | no fix |
| Chainguard | celeborn-0.6 | no fix |
| Chainguard | celeborn-0.7 | 0.7.0-r8 |
| Chainguard | celeborn-0.7 | no fix |
| Chainguard | commercial-elasticsearch-8.17 | no fix |
| Chainguard | commercial-elasticsearch-8.19 | 8.19.22-r0 |
| Chainguard | commercial-elasticsearch-9.2 | no fix |
| Chainguard | commercial-elasticsearch-9.3 | no fix |
| Chainguard | commercial-elasticsearch-9.4 | 9.4.8-r0 |
| Chainguard | commercial-elasticsearch-9.5 | 9.5.5-r0 |
| Chainguard | cruise-control-fips-jars | 2.5.146-r5 |
| Chainguard | cruise-control-jars | 2.5.146-r4 |
| Chainguard | drain-cleaner | 1.6.1-r3 |
| Chainguard | drain-cleaner-fips | 1.6.1-r2 |
| Chainguard | druid | 37.0.0-r56 |
| Chainguard | elasticsearch-8.19 | 8.19.21-r1 |
| Chainguard | elasticsearch-8.19-iamguarded-fips | 8.19.21-r1 |
| Chainguard | elasticsearch-9.2 | no fix |
| Chainguard | elasticsearch-9.2-iamguarded-fips | no fix |
| Chainguard | elasticsearch-9.3 | no fix |
| Chainguard | elasticsearch-9.3-iamguarded-fips | no fix |
| Chainguard | elasticsearch-9.4 | 9.4.8-r0 |
| Chainguard | elasticsearch-9.4-iamguarded-fips | 9.4.8-r0 |
| Chainguard | elasticsearch-9.5 | 9.5.5-r0 |
| Chainguard | elasticsearch-9.5-iamguarded | 9.5.3-r1 |
| Chainguard | elasticsearch-9.5-iamguarded-fips | 9.5.5-r0 |
| Chainguard | elasticsearch-fips-8.19 | 8.19.21-r1 |
| Chainguard | elasticsearch-fips-9.2 | no fix |
| Chainguard | elasticsearch-fips-9.3 | no fix |
| Chainguard | elasticsearch-fips-9.4 | 9.4.8-r0 |
| Chainguard | elasticsearch-fips-9.5 | 9.5.5-r0 |
| Chainguard | floci | 2.0.1-r1 |
| Chainguard | floci-az | 0.12.0-r1 |
| Chainguard | flyway | 13.6.0-r2 |
| Chainguard | flyway-fips | 13.6.0-r1 |
| Chainguard | ghidra | 12.1.3-r3 |
| Chainguard | hadoop-3.5 | no fix |
| Chainguard | hadoop-fips-3.3.6 | no fix |
| Chainguard | hadoop-fips-3.4.2 | no fix |
| Chainguard | hadoop-fips-3.5 | 3.5.0-r14 |
| Chainguard | hadoop-fips-3.5 | no fix |
| Chainguard | hono-adapter-mqtt | 2.7.0-r40 |
| Chainguard | hono-cli | 2.7.0-r40 |
| Chainguard | hono-service-auth | 2.7.0-r40 |
| Chainguard | hono-service-command-router | 2.7.0-r40 |
| Chainguard | hono-service-device-registry-jdbc | 2.7.0-r40 |
| Chainguard | kafka-3.7 | 3.7.2-r59 |
| Chainguard | kafka-3.8 | 3.8.1-r61 |
| Chainguard | kafka-3.9 | 3.9.2-r15 |
| Chainguard | kafka-strimzi-compat | no fix |
| Chainguard | kafka-strimzi-compat | 1.2.0-r5 |
| Chainguard | kafka_exporter-strimzi-compat | 1.2.0-r5 |
| Chainguard | kafka_exporter-strimzi-compat | 1.2.0-r4 |
| Chainguard | kayenta-2025.2 | 2025.2.4-r10 |
| Chainguard | kayenta-2025.4 | 2025.4.6-r15 |
| Chainguard | kayenta-2026.0 | no fix |
| Chainguard | kayenta-2026.1 | 2026.1.2-r6 |
| Chainguard | kayenta-fips-2025.2 | no fix |
| Chainguard | kayenta-fips-2025.4 | no fix |
| Chainguard | kayenta-fips-2026.0 | 2026.0.5-r4 |
| Chainguard | kayenta-fips-2026.1 | 2026.1.2-r6 |
| Chainguard | keycloak-26.5 | 26.5.7-r7 |
| Chainguard | keycloak-26.5-iamguarded-compat | 26.5.7-r7 |
| Chainguard | keycloak-26.5-operator | 26.5.7-r7 |
| Chainguard | keycloak-26.6 | 26.6.6-r1 |
| Chainguard | keycloak-26.6-iamguarded-compat | 26.6.6-r1 |
| Chainguard | keycloak-26.6-operator | 26.6.6-r1 |
| Chainguard | keycloak-26.7 | 26.7.3-r1 |
| Chainguard | keycloak-26.7-iamguarded-compat | 26.7.3-r1 |
| Chainguard | keycloak-26.7-operator | 26.7.3-r1 |
| Chainguard | keycloak-fips-26.5 | 26.5.7-r13 |
| Chainguard | keycloak-fips-26.5-iamguarded-fips | 26.5.7-r13 |
| Chainguard | keycloak-fips-26.5-operator | 26.5.7-r13 |
| Chainguard | keycloak-fips-26.6 | 26.6.6-r1 |
| Chainguard | keycloak-fips-26.6-iamguarded-fips | 26.6.6-r1 |
| Chainguard | keycloak-fips-26.6-operator | 26.6.6-r1 |
| Chainguard | keycloak-fips-26.7 | 26.7.3-r1 |
| Chainguard | keycloak-fips-26.7-iamguarded-fips | 26.7.3-r1 |
| Chainguard | keycloak-fips-26.7-operator | 26.7.3-r1 |
| Chainguard | knative-kafka-broker-1.20-dispatcher-loom | 1.20.3-r17 |
| Chainguard | knative-kafka-broker-1.20-receiver-loom | 1.20.3-r17 |
| Chainguard | knative-kafka-broker-1.22-dispatcher-loom | 1.22.3-r13 |
| Chainguard | knative-kafka-broker-1.22-receiver-loom | 1.22.3-r13 |
| Chainguard | knative-kafka-broker-1.23-dispatcher-loom | 1.23.1-r3 |
| Chainguard | knative-kafka-broker-1.23-receiver-loom | 1.23.1-r3 |
| Chainguard | knative-kafka-broker-fips-1.20-dispatcher-loom | 1.20.3-r15 |
| Chainguard | knative-kafka-broker-fips-1.20-receiver-loom | 1.20.3-r15 |
| Chainguard | knative-kafka-broker-fips-1.22-dispatcher-loom | 1.22.3-r9 |
| Chainguard | knative-kafka-broker-fips-1.22-receiver-loom | 1.22.3-r9 |
| Chainguard | knative-kafka-broker-fips-1.23-dispatcher-loom | 1.23.1-r4 |
| Chainguard | knative-kafka-broker-fips-1.23-receiver-loom | 1.23.1-r4 |
| Chainguard | logstash-9.2 | 9.2.8-r6 |
| Chainguard | logstash-9.2-iamguarded-compat | 9.2.8-r6 |
| Chainguard | logstash-9.2-with-output-opensearch | 9.2.8-r6 |
| Chainguard | logstash-9.3 | no fix |
| Chainguard | logstash-9.3-iamguarded-compat | no fix |
| Chainguard | management-api-for-apache-cassandra-4.0 | 0.1.125-r3 |
| Chainguard | neo4j-2026.02 | 2026.02.3-r4 |
| Chainguard | neo4j-2026.03 | 2026.03.1-r4 |
| Chainguard | pinot | 1.5.1-r19 |
| Chainguard | pinot-fips | 1.5.1-r15 |
| Chainguard | prometheus-jmx-exporter-strimzi-compat | 1.6.0-r0 |
| Chainguard | ranger | no fix |
| Chainguard | request-9047-keycloak-fips-26.5 | 26.5.7-r27 |
| Chainguard | request-9047-keycloak-fips-26.5-iamguarded-fips | 26.5.7-r27 |
| Chainguard | request-9047-keycloak-fips-26.5-operator | 26.5.7-r27 |
| Chainguard | request-9047-keycloak-fips-26.6 | 26.6.6-r2 |
| Chainguard | request-9047-keycloak-fips-26.6-iamguarded-fips | 26.6.6-r2 |
| Chainguard | request-9047-keycloak-fips-26.6-operator | 26.6.6-r2 |
| Chainguard | request-9047-keycloak-fips-26.7 | 26.7.3-r1 |
| Chainguard | request-9047-keycloak-fips-26.7-iamguarded-fips | 26.7.3-r1 |
| Chainguard | request-9047-keycloak-fips-26.7-operator | 26.7.3-r1 |
| Chainguard | seata-server | 2.7.0-r9 |
| Chainguard | sonarqube | 26.8.0.126808-r3 |
| Chainguard | spark-3.5-scala-2.12 | 3.5.9-r5 |
| Chainguard | spark-3.5-scala-2.13 | 3.5.9-r5 |
| Chainguard | spark-4.0-scala-2.13 | 4.0.4-r4 |
| Chainguard | spark-4.2-scala-2.13 | 4.2.0-r10 |
| Chainguard | spark-fips-3.5-scala-2.12 | 3.5.8-r9 |
| Chainguard | spark-fips-3.5-scala-2.13 | 3.5.8-r9 |
| Chainguard | spark-fips-4.1-scala-2.13 | 4.1.2-r9 |
| Chainguard | spark-fips-4.2-scala-2.13 | 4.2.0-r9 |
| Chainguard | strimzi-kafka-operator | 1.2.0-r5 |
| Chainguard | strimzi-kafka-operator | no fix |
| Chainguard | strimzi-kafka-operator-cluster-operator | 1.2.0-r4 |
| Chainguard | strimzi-kafka-operator-cluster-operator | 1.2.0-r5 |
| Chainguard | strimzi-kafka-operator-kafka-agent | no fix |
| Chainguard | strimzi-kafka-operator-kafka-agent | 1.2.0-r5 |
| Chainguard | strimzi-kafka-operator-kafka-base | 1.2.0-r5 |
| Chainguard | strimzi-kafka-operator-kafka-init | 1.2.0-r5 |
| Chainguard | strimzi-kafka-operator-kafka-init | 1.2.0-r4 |
| Chainguard | strimzi-kafka-operator-kafka-init | no fix |
| Chainguard | strimzi-kafka-operator-kafka-thirdparty-libs | 1.2.0-r5 |
| Chainguard | strimzi-kafka-operator-kafka-thirdparty-libs-cc | 1.2.0-r5 |
| Chainguard | strimzi-kafka-operator-kafka-thirdparty-libs-cc | 1.2.0-r4 |
| Chainguard | strimzi-kafka-operator-topic-operator | 1.2.0-r4 |
| Chainguard | strimzi-kafka-operator-topic-operator | 1.2.0-r5 |
| Chainguard | strimzi-kafka-operator-tracing-agent | 1.2.0-r5 |
| Chainguard | strimzi-kafka-operator-user-operator | 1.2.0-r5 |
| Chainguard | tez | 0.10.5-r30 |
| Chainguard | trino-plugin-opensearch | no fix |
| Chainguard | zaproxy | no fix |
| Chainguard | zookeeper-3.8 | 3.8.6-r15 |
| Chainguard | zookeeper-3.9 | 3.9.5-r14 |
| Chainguard | zookeeper-fips-3.8 | 3.8.6-r14 |
| Chainguard | zookeeper-fips-3.9 | 3.9.5-r10 |
| Debian 12 | netty | no fix |
| Debian 13 | netty | no fix |
| Debian 14 | netty | no fix |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise Module for Package Hub 15 SP7 | netty | 4.1.138-150200.4.56.1 |
| SUSE Linux Enterprise Server 15 SP4-LTSS | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise Server 15 SP5-LTSS | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise Server 15 SP6-LTSS | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | netty-tcnative | 2.0.84-150200.3.51.1 |
| Ubuntu 26.10 | netty | no fix |
| Ubuntu Pro 14.04 LTS | netty | no fix |
| Ubuntu Pro 16.04 LTS | netty | no fix |
| Ubuntu Pro 18.04 LTS | netty | no fix |
| Ubuntu Pro 20.04 LTS | netty | no fix |
| Ubuntu Pro 22.04 LTS | netty | no fix |
| Ubuntu Pro 24.04 LTS | netty | no fix |
| Ubuntu Pro 26.04 LTS | netty | no fix |
| Wolfi | akhq | 0.28.0-r8 |
| Wolfi | cassandra-5.0 | 5.0.9-r7 |
| Wolfi | cassandra-reaper | 5.0.1-r1 |
| Wolfi | celeborn-0.6 | no fix |
| Wolfi | druid | 37.0.0-r56 |
| Wolfi | flyway | 13.6.0-r2 |
| Wolfi | kafka-strimzi-compat | no fix |
| Wolfi | kafka-strimzi-compat | 1.2.0-r5 |
| Wolfi | kafka_exporter-strimzi-compat | 1.2.0-r4 |
| Wolfi | kafka_exporter-strimzi-compat | 1.2.0-r5 |
| Wolfi | keycloak-26.5 | 26.5.7-r7 |
| Wolfi | keycloak-26.5-iamguarded-compat | 26.5.7-r7 |
| Wolfi | keycloak-26.5-operator | 26.5.7-r7 |
| Wolfi | keycloak-26.6 | 26.6.6-r1 |
| Wolfi | keycloak-26.6-iamguarded-compat | 26.6.6-r1 |
| Wolfi | keycloak-26.6-operator | 26.6.6-r1 |
| Wolfi | logstash-9.3 | no fix |
| Wolfi | logstash-9.3-iamguarded-compat | no fix |
| Wolfi | prometheus-jmx-exporter-strimzi-compat | 1.6.0-r0 |
| Wolfi | sonarqube | 26.8.0.126808-r3 |
| Wolfi | spark-4.0-scala-2.13 | 4.0.4-r4 |
| Wolfi | strimzi-kafka-operator | no fix |
| Wolfi | strimzi-kafka-operator | 1.2.0-r5 |
| Wolfi | strimzi-kafka-operator-cluster-operator | 1.2.0-r4 |
| Wolfi | strimzi-kafka-operator-cluster-operator | 1.2.0-r5 |
| Wolfi | strimzi-kafka-operator-kafka-agent | no fix |
| Wolfi | strimzi-kafka-operator-kafka-agent | 1.2.0-r5 |
| Wolfi | strimzi-kafka-operator-kafka-base | 1.2.0-r5 |
| Wolfi | strimzi-kafka-operator-kafka-init | 1.2.0-r4 |
| Wolfi | strimzi-kafka-operator-kafka-init | no fix |
| Wolfi | strimzi-kafka-operator-kafka-init | 1.2.0-r5 |
| Wolfi | strimzi-kafka-operator-kafka-thirdparty-libs | 1.2.0-r5 |
| Wolfi | strimzi-kafka-operator-kafka-thirdparty-libs-cc | 1.2.0-r4 |
| Wolfi | strimzi-kafka-operator-kafka-thirdparty-libs-cc | 1.2.0-r5 |
| Wolfi | strimzi-kafka-operator-topic-operator | 1.2.0-r4 |
| Wolfi | strimzi-kafka-operator-topic-operator | 1.2.0-r5 |
| Wolfi | strimzi-kafka-operator-tracing-agent | 1.2.0-r5 |
| Wolfi | strimzi-kafka-operator-user-operator | 1.2.0-r5 |
| Wolfi | tez | 0.10.5-r30 |
| Wolfi | trino-plugin-opensearch | no fix |
| Wolfi | zookeeper-3.9 | 3.9.5-r14 |
| openSUSE Tumbleweed | netty | 4.1.138-1.1 |