--- id: CVE-2026-50560 title: >- netty-codec-http2: Netty: Denial of Service due to HTTP/2 max header size handling (CVE-2026-50560) summary: >- A flaw was found in Netty, a network application framework. A remote attacker can exploit a vulnerability in the HTTP/2 (Hypertext Transfer Protocol version 2) maximum header size handling. By sending a specific SETTINGS_MAX_HEADER_LIST_SI… severity: medium cvss: 5.3 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L' cvssSource: vendor cwe: CWE-770 vendor: Red Hat product: OpenShift Serverless affected: - cryostat 4 - openshift_serverless - amq_broker 7 - build_of_apache_camel_hawtio 4 - build_of_apache_camel_4_for_quarkus 3 - build_of_apache_camel_for_spring_boot 4 - build_of_apicurio_registry 3 - build_of_debezium 3 - build_of_keycloak - data_grid 8 - fuse 7 - jboss_enterprise_application_platform 7 - jboss_enterprise_application_platform_expansion_pack - openshift_ai_rhoai - openshift_dev_spaces - single_sign_on 7 - streams_for_apache_kafka 2 - streams_for_apache_kafka 3 - jboss_enterprise_application_platform 8.1 - build_of_quarkus 3.27.4.SP1 - build_of_quarkus 3.33.2.SP1 patched: - jboss_enterprise_application_platform 8.1 - build_of_quarkus 3.27.4.SP1 - build_of_quarkus 3.33.2.SP1 published: '2026-06-12' updated: '2026-09-07' sourceUpdated: '2026-09-07T14:27:19+00:00' source: CSAF sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-50560.json' references: - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-50560.json - url: 'https://access.redhat.com/security/cve/CVE-2026-50560' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2488407' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-50560' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-50560' - url: 'https://github.com/netty/netty/releases/tag/netty-4.1.135.Final' - url: 'https://github.com/netty/netty/releases/tag/netty-4.2.15.Final' - url: 'https://github.com/netty/netty/security/advisories/GHSA-563q-j3cm-6jxm' - url: 'https://www.rfc-editor.org/rfc/rfc9113.html#name-defined-settings' - url: 'https://access.redhat.com/errata/RHSA-2026:50085' - url: 'https://access.redhat.com/errata/RHSA-2026:26018' - url: 'https://access.redhat.com/errata/RHSA-2026:26017' - url: 'https://github.com/advisories/GHSA-563q-j3cm-6jxm' tags: - csaf - vex - red-hat - ghsa - maven epss: 0.00524 epssPercentile: 0.41998 aliases: - GHSA-563q-j3cm-6jxm ecosystem: maven ingestedAt: '2026-07-07T15:41:58.402Z' --- ## Overview A flaw was found in Netty, a network application framework. A remote attacker can exploit a vulnerability in the HTTP/2 (Hypertext Transfer Protocol version 2) maximum header size handling. By sending a specific SETTINGS_MAX_HEADER_LIST_SIZE setting, an attacker can cause Netty to produce an exception when writing response headers. This issue is similar to an HTTP/2 Rapid Reset attack and can lead to a Denial of Service (DoS). ## Vendor advisories - **RHSA-2026:50085** · Red Hat · fixed in: Red Hat JBoss Enterprise Application Platform 8.1 · released 2026-08-04 · [advisory](https://access.redhat.com/errata/RHSA-2026:50085) - **RHSA-2026:26018** · Red Hat · fixed in: Red Hat build of Quarkus 3.27.4.SP1 · released 2026-06-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:26018) - **RHSA-2026:26017** · Red Hat · fixed in: Red Hat build of Quarkus 3.33.2.SP1 · released 2026-06-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:26017) - **Red Hat VEX** · Moderate · affected: Cryostat 4, OpenShift Serverless, Red Hat AMQ Broker 7, Red Hat build of Apache Camel - HawtIO 4, Red Hat build of Apache Camel 4 for Quarkus 3, Red Hat build of Apache Camel for Spring Boot 4, … · no fix planned: Cryostat 4, OpenShift Serverless, Red Hat AMQ Broker 7, Red Hat build of Apache Camel - HawtIO 4, … · updated 2026-09-07 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-50560.json) **netty-codec-http2: Netty: Denial of Service due to HTTP/2 max header size handling** — rated Moderate by Red Hat. Released 2026-06-12, updated 2026-09-07. Affected: - Cryostat 4 - OpenShift Serverless - Red Hat AMQ Broker 7 - Red Hat build of Apache Camel - HawtIO 4 - Red Hat build of Apache Camel 4 for Quarkus 3 - Red Hat build of Apache Camel for Spring Boot 4 - Red Hat build of Apicurio Registry 3 - Red Hat build of Debezium 3 - Red Hat Build of Keycloak - Red Hat Data Grid 8 - Red Hat Fuse 7 - Red Hat JBoss Enterprise Application Platform 7 - Red Hat JBoss Enterprise Application Platform Expansion Pack - Red Hat OpenShift AI (RHOAI) - Red Hat OpenShift Dev Spaces - Red Hat Single Sign-On 7 - streams for Apache Kafka 2 - streams for Apache Kafka 3 Fixed: - Red Hat JBoss Enterprise Application Platform 8.1 - Red Hat build of Quarkus 3.27.4.SP1 - Red Hat build of Quarkus 3.33.2.SP1 No fix planned: - Cryostat 4 - OpenShift Serverless - Red Hat AMQ Broker 7 - Red Hat build of Apache Camel - HawtIO 4 - Red Hat build of Apache Camel 4 for Quarkus 3 - Red Hat build of Apache Camel for Spring Boot 4 - Red Hat build of Apicurio Registry 3 - Red Hat build of Debezium 3 - Red Hat Build of Keycloak - Red Hat Data Grid 8 - Red Hat Fuse 7 - Red Hat JBoss Enterprise Application Platform 7 - Red Hat JBoss Enterprise Application Platform Expansion Pack - Red Hat OpenShift AI (RHOAI) - Red Hat OpenShift Dev Spaces - Red Hat Single Sign-On 7 - streams for Apache Kafka 2 - streams for Apache Kafka 3 Not affected: - Red Hat Enterprise Linux AI (RHEL AI) 3 - Red Hat OpenShift Dev Spaces ## Remediation Before applying the update, make sure all previously released errata relevant to your system have been applied. Also, back up your existing installation, including all applications, configuration files, databases and database settings. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258 https://access.redhat.com/errata/RHSA-2026:50085 Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258 https://access.redhat.com/errata/RHSA-2026:26018 Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258 https://access.redhat.com/errata/RHSA-2026:26017 Workarounds / mitigations: - Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. ## Package advisory (CVE-2026-50560) Affected packages: - `io.netty:netty-codec-http2 >= 4.2.0.Final, <= 4.2.14.Final` - `io.netty:netty-codec-http2 <= 4.1.134.Final` Patched in: - `io.netty:netty-codec-http2 4.2.15.Final` - `io.netty:netty-codec-http2 4.1.135.Final` Source: https://github.com/advisories/GHSA-563q-j3cm-6jxm