--- id: CVE-2026-56819 title: >- io.netty/netty-codec-http2: Netty: Denial of Service via HTTP/2 DATA frame memory leak (CVE-2026-56819) summary: >- A flaw was found in Netty, a network application framework. A remote, unauthenticated attacker can exploit this vulnerability by sending specially crafted HTTP/2 DATA frames to applications that use Netty and have HTTP/2 content decompress… severity: high cvss: 7.5 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H' cvssSource: vendor cwe: - CWE-911 - CWE-400 vendor: Red Hat product: Red Hat OpenShift Dev Spaces 3.30 affected: - openshift_serverless - build_of_apache_camel_hawtio 4 - build_of_apache_camel_4_for_quarkus 3 - build_of_apicurio_registry 3 - build_of_debezium 3 - build_of_keycloak - enterprise_linux_ai_rhel_ai 3 - 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 - cryostat_4_on_rhel 9 - amq_broker 7.14.1 - data_grid 8.6.3 - openshift_ai 2.25 - openshift_dev_spaces 3.30 - build_of_apache_camel_4_18_3_for_spring_boot 3.5.16 - build_of_quarkus 3.27.4.SP3 - build_of_quarkus 3.33.2.SP3 - streams_for_apache_kafka 3.2.1 patched: - cryostat_4_on_rhel 9 - amq_broker 7.14.1 - data_grid 8.6.3 - openshift_ai 2.25 - openshift_dev_spaces 3.30 - build_of_apache_camel_4_18_3_for_spring_boot 3.5.16 - build_of_quarkus 3.27.4.SP3 - build_of_quarkus 3.33.2.SP3 - streams_for_apache_kafka 3.2.1 published: '2026-07-21' updated: '2026-09-25' sourceUpdated: '2026-09-25T15:29:14+00:00' source: CSAF sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-56819.json' references: - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-56819.json - url: 'https://access.redhat.com/security/cve/CVE-2026-56819' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2505980' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-56819' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-56819' - url: >- https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003bhttps://github.com/netty/netty/releases/tag/netty-4.2.16.Final - url: >- https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6 - url: 'https://github.com/netty/netty/releases/tag/netty-4.1.136.Final' - url: 'https://github.com/netty/netty/releases/tag/netty-4.2.16.Final' - url: 'https://github.com/netty/netty/security/advisories/GHSA-93wv-jw9v-4972' - url: 'https://access.redhat.com/errata/RHSA-2026:68333' - url: 'https://access.redhat.com/errata/RHSA-2026:66488' - url: 'https://access.redhat.com/errata/RHSA-2026:69296' - url: 'https://access.redhat.com/errata/RHSA-2026:65126' - url: 'https://access.redhat.com/errata/RHSA-2026:62260' - url: 'https://access.redhat.com/errata/RHSA-2026:68754' - url: 'https://access.redhat.com/errata/RHSA-2026:54622' - url: 'https://access.redhat.com/errata/RHSA-2026:47189' - url: 'https://access.redhat.com/errata/RHSA-2026:47172' - url: 'https://access.redhat.com/errata/RHSA-2026:54435' - url: 'https://access.redhat.com/errata/RHSA-2026:48118' - url: >- https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b - url: 'https://github.com/advisories/GHSA-93wv-jw9v-4972' tags: - csaf - vex - red-hat - exploit-available - ghsa - maven epss: 0.00665 epssPercentile: 0.49681 exploits: github: 1 githubRepos: - 'https://github.com/xiaoqiMikko/netty-http2-check' checkedAt: '2026-09-26T07:44:30.795Z' exploitAvailable: true aliases: - GHSA-93wv-jw9v-4972 ecosystem: maven ingestedAt: '2026-07-31T16:59:59.858Z' --- ## Overview A flaw was found in Netty, a network application framework. A remote, unauthenticated attacker can exploit this vulnerability by sending specially crafted HTTP/2 DATA frames to applications that use Netty and have HTTP/2 content decompression enabled. This can lead to memory exhaustion, causing the application to crash and resulting in a Denial of Service (DoS). The issue occurs because the framework fails to release retained memory buffers when processing DATA frames for a stream whose decompressor has already been closed. ## Vendor advisories - **RHSA-2026:68333** · Red Hat · fixed in: Cryostat 4 on RHEL 9 · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:68333) - **RHSA-2026:66488** · Red Hat · fixed in: Red Hat AMQ Broker 7.14.1 · released 2026-09-10 · [advisory](https://access.redhat.com/errata/RHSA-2026:66488) - **RHSA-2026:69296** · Red Hat · fixed in: Red Hat Data Grid 8.6.3 · released 2026-09-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:69296) - **RHSA-2026:65126** · Red Hat · fixed in: Red Hat OpenShift AI 2.25 · released 2026-09-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:65126) - **RHSA-2026:62260** · Red Hat · fixed in: Red Hat OpenShift Dev Spaces 3.30 · released 2026-09-01 · [advisory](https://access.redhat.com/errata/RHSA-2026:62260) - **RHSA-2026:68754** · Red Hat · fixed in: Red Hat OpenShift Dev Spaces 3.30 · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68754) - **RHSA-2026:54622** · Red Hat · fixed in: Red Hat build of Apache Camel 4.18.3 for Spring Boot 3.5.16 · released 2026-08-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:54622) - **RHSA-2026:47189** · Red Hat · fixed in: Red Hat build of Quarkus 3.27.4.SP3 · released 2026-07-29 · [advisory](https://access.redhat.com/errata/RHSA-2026:47189) - **RHSA-2026:47172** · Red Hat · fixed in: Red Hat build of Quarkus 3.33.2.SP3 · released 2026-07-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:47172) - **RHSA-2026:54435** · Red Hat · fixed in: Streams for Apache Kafka 3.2.1 · released 2026-08-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:54435) - **Red Hat VEX** · Important · affected: OpenShift Serverless, Red Hat build of Apache Camel - HawtIO 4, Red Hat build of Apache Camel 4 for Quarkus 3, Red Hat build of Apicurio Registry 3, Red Hat build of Debezium 3, Red Hat Build of Keycloak, … · no fix planned: Red Hat Single Sign-On 7, Red Hat build of Debezium 3, Red Hat JBoss Enterprise Application Platform 7, OpenShift Serverless, … · updated 2026-09-25 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-56819.json) - **RHSA-2026:48118** · Red Hat · fixed in: Red Hat Build of Apache Camel 4.18 for Quarkus 3.33 · released 2026-07-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:48118) **io.netty/netty-codec-http2: Netty: Denial of Service via HTTP/2 DATA frame memory leak** — rated Important by Red Hat. Released 2026-07-21, updated 2026-09-25. Affected: - OpenShift Serverless - Red Hat build of Apache Camel - HawtIO 4 - Red Hat build of Apache Camel 4 for Quarkus 3 - Red Hat build of Apicurio Registry 3 - Red Hat build of Debezium 3 - Red Hat Build of Keycloak - Red Hat Enterprise Linux AI (RHEL AI) 3 - 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 Fixed: - Cryostat 4 on RHEL 9 - Red Hat AMQ Broker 7.14.1 - Red Hat Data Grid 8.6.3 - Red Hat OpenShift AI 2.25 - Red Hat OpenShift Dev Spaces 3.30 - Red Hat build of Apache Camel 4.18.3 for Spring Boot 3.5.16 - Red Hat build of Quarkus 3.27.4.SP3 - Red Hat build of Quarkus 3.33.2.SP3 - Streams for Apache Kafka 3.2.1 No fix planned: - Red Hat Single Sign-On 7 - Red Hat build of Debezium 3 - Red Hat JBoss Enterprise Application Platform 7 - OpenShift Serverless - Red Hat build of Apache Camel - HawtIO 4 - Red Hat build of Apache Camel 4 for Quarkus 3 - Red Hat build of Apicurio Registry 3 - Red Hat Build of Keycloak - Red Hat Enterprise Linux AI (RHEL AI) 3 - Red Hat JBoss Enterprise Application Platform Expansion Pack - Red Hat OpenShift AI (RHOAI) - Red Hat OpenShift Dev Spaces - streams for Apache Kafka 2 Not affected: - Cryostat 4 on RHEL 9 - Red Hat OpenShift AI 2.25 - Red Hat OpenShift Dev Spaces 3.30 - Red Hat OpenShift AI (RHOAI) ## Remediation 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-2026:68333 Before applying the update, back up your existing installation, including all applications, configuration files, databases and database settings. The References section of this erratum contains a download link (you must log in to download the update). https://access.redhat.com/errata/RHSA-2026:66488 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-2026:69296 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-2026-56819) Affected packages: - `io.netty:netty-codec-http2 >= 4.2.0, <= 4.2.15.Final` - `io.netty:netty-codec-http2 >= 4.1.0.Final, <= 4.1.135.Final` Patched in: - `io.netty:netty-codec-http2 4.2.16.Final` - `io.netty:netty-codec-http2 4.1.136.Final` Source: https://github.com/advisories/GHSA-93wv-jw9v-4972