Uncontrolled resource consumption in netty
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 16 fixed, 11 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-400.
Summary
Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and 4.1.0.Final through 4.1.135.Final, a remote unauthenticated peer can leak one direct `ByteBuf` per HTTP/2 `DATA` frame in applications that enable HTTP/2 content decompression via `DelegatingDecompressorFrameListener`. When a `DATA` frame is processed for a stream whose decompressor has already been closed, `Http2Decompressor.decompress(...)` calls `decompressor.writeInbound(data.retain())` and does not release the retained buffer on the error path, eventually exhausting direct memory and crashing the JVM. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| netty | netty | 4.2.0.Final to before 4.2.16.Final; 4.1.0.Final to before 4.1.136.Final | 4.2.16.Final, 4.1.136.Final | Patch available | CNA |
| — | io.netty:netty-codec-http2 (Maven) | 4.2.0 to before 4.2.16.Final | 4.2.16.Final | Patch available | GHSA-93wv-jw9v-4972 |
| — | io.netty:netty-codec-http2 (Maven) | 4.1.0.Final to before 4.1.136.Final | 4.1.136.Final | Patch available | GHSA-93wv-jw9v-4972 |
- netty Vendornetty Affected 4.2.0.Final to before 4.2.16.Final; 4.1.0.Final to before 4.1.136.Final Fixed in 4.2.16.Final, 4.1.136.Final Patch available CNA
- io.netty:netty-codec-http2 (Maven) Vendor— Affected 4.2.0 to before 4.2.16.Final Fixed in 4.2.16.Final Patch available GHSA-93wv-jw9v-4972
- io.netty:netty-codec-http2 (Maven) Vendor— Affected 4.1.0.Final to before 4.1.136.Final Fixed in 4.1.136.Final Patch available GHSA-93wv-jw9v-4972
Remediation
- Fix · CNA netty (netty) Fixed in 4.2.16.Final, 4.1.136.Final
- Fix · GHSA-93wv-jw9v-4972 io.netty:netty-codec-http2 (Maven) Fixed in 4.2.16.Final Advisory →
- Fix · GHSA-93wv-jw9v-4972 io.netty:netty-codec-http2 (Maven) Fixed in 4.1.136.Final Advisory →
Red Hat 18 advisories
- RHSA-2026:90321 Released 2026-10-26 · Red Hat rating CriticalRed Hat OpenShift Dev Spaces 3.31.0 Release.
- Red Hat OpenShift Dev Spaces 3.31 registry.redhat.io/devspaces/code-rhel9, registry.redhat.io/devspaces/dashboard-rhel9, registry.redhat.io/devspaces/jetbrains-ide-rhel9 +8
- RHSA-2026:87410 Released 2026-10-21 · Red Hat rating CriticalRHOAI 2.25.12 - Red Hat OpenShift AI
- Red Hat OpenShift AI 2.25 registry.redhat.io/rhoai/odh-built-in-detector-rhel9, registry.redhat.io/rhoai/odh-caikit-nlp-rhel9, registry.redhat.io/rhoai/odh-codeflare-operator-rhel9 +47
- RHSA-2026:84734 Released 2026-10-19 · Red Hat rating CriticalRHOAI 3.4.5 - Red Hat OpenShift AI
- Red Hat OpenShift AI 3.4 registry.redhat.io/rhoai/odh-ai-gateway-payload-processing-rhel9, registry.redhat.io/rhoai/odh-automl-rhel9, registry.redhat.io/rhoai/odh-autorag-rhel9 +47
Show 15 more Red Hat advisories
- RHSA-2026:76637 Released 2026-10-06 · Red Hat rating ImportantApicurio Registry (container images) release and security update [ 3.3.3 GA ]
- Red Hat build of Apicurio Registry 3.3.3
- RHSA-2026:70421 Released 2026-09-22 · Red Hat rating ImportantRed Hat JBoss Enterprise Application Platform 8.1.8 XP 6.0.6.GA release
- Red Hat JBoss Enterprise Application Platform 8.1
- RHSA-2026:69296 Released 2026-09-21 · Red Hat rating ImportantRed Hat Data Grid 8.6.3 security update
- Red Hat Data Grid 8.6.3
- RHSA-2026:68754 Released 2026-09-17 · Red Hat rating ImportantRed Hat OpenShift Dev Spaces 3.30.1 Release.
- Red Hat OpenShift Dev Spaces 3.30 registry.redhat.io/devspaces/code-rhel9, registry.redhat.io/devspaces/dashboard-rhel9, registry.redhat.io/devspaces/openvsx-rhel9 +2
- RHSA-2026:68333 Released 2026-09-16 · Red Hat rating ImportantRed Hat build of Cryostat security update
- Cryostat 4 on RHEL 9 cryostat/cryostat-agent-init-rhel9, cryostat/cryostat-grafana-dashboard-rhel9, cryostat/cryostat-openshift-console-plugin-rhel9 +5
- RHSA-2026:66488 Released 2026-09-10 · Red Hat rating ImportantRed Hat AMQ Broker 7.14.1 release and security update
- Red Hat AMQ Broker 7.14.1
- RHSA-2026:65126 Released 2026-09-08 · Red Hat rating ImportantRHOAI 2.25.11 - Red Hat OpenShift AI
- Red Hat OpenShift AI 2.25 registry.redhat.io/rhoai/odh-built-in-detector-rhel9, registry.redhat.io/rhoai/odh-caikit-tgis-serving-rhel9, registry.redhat.io/rhoai/odh-dashboard-rhel9 +47
- RHSA-2026:62260 Released 2026-09-01 · Red Hat rating ImportantRed Hat OpenShift Dev Spaces 3.30.0 Release.
- Red Hat OpenShift Dev Spaces 3.30 registry.redhat.io/devspaces/code-rhel9, registry.redhat.io/devspaces/configbump-rhel9, registry.redhat.io/devspaces/dashboard-rhel9 +7
- RHSA-2026:54622 Released 2026-08-13 · Red Hat rating ImportantRed Hat Build of Apache Camel 4.18.3 for Spring Boot release.
- Red Hat build of Apache Camel 4.18.3 for Spring Boot 3.5.16
- RHSA-2026:54435 Released 2026-08-12 · Red Hat rating ImportantStreams for Apache Kafka 3.2.1 release and security update
- Streams for Apache Kafka 3.2.1
- RHSA-2026:50846 Released 2026-08-05 · Red Hat rating ImportantRed Hat build of Keycloak 26.4.14 Security Update
- Red Hat build of Keycloak 26.4.14
- RHSA-2026:50848 Released 2026-08-05 · Red Hat rating ImportantRed Hat build of Keycloak 26.6.5 Security Update
- Red Hat build of Keycloak 26.6.5
- RHSA-2026:48118 Released 2026-07-30 · Red Hat rating ImportantRed Hat Build of Apache Camel 4.18.3 for Quarkus 3.33 update is now available (RHBQ 3.33.2.SP3)
- Red Hat Build of Apache Camel 3.33.2.SP3 io.netty.netty-codec-haproxy-4.1.136.Final-redhat-00001.jar, io.netty.netty-codec-http-4.1.136.Final-redhat-00001.jar, io.netty.netty-codec-http2-4.1.136.Final-redhat-00001.jar +9
- RHSA-2026:47172 Released 2026-07-30 · Red Hat rating ImportantRed Hat build of Quarkus 3.33.2.SP3 security update
- Red Hat build of Quarkus 3.33.2.SP3 io.netty.netty-codec-haproxy-4.1.136.Final-redhat-00001.jar, io.netty.netty-codec-http-4.1.136.Final-redhat-00001.jar, io.netty.netty-codec-http2-4.1.136.Final-redhat-00001.jar +3
- RHSA-2026:47189 Released 2026-07-29 · Red Hat rating ImportantRed Hat build of Quarkus 3.27.4.SP3 security update
- Red Hat build of Quarkus 3.27.4.SP3 io.netty.netty-codec-haproxy-4.1.136.Final-redhat-00001.jar, io.netty.netty-codec-http-4.1.136.Final-redhat-00001.jar, io.netty.netty-codec-http2-4.1.136.Final-redhat-00001.jar +3
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| OpenShift Serverless | Affected | No fix yet |
| Red Hat Build of Keycloak | Affected | No fix yet |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | Affected | No fix yet |
| Red Hat JBoss Enterprise Application Platform 7 | Affected | No fix yet: Fix deferred |
| Red Hat JBoss Enterprise Application Platform Expansion Pack | Affected | No fix yet |
| Red Hat OpenShift AI (RHOAI) | Affected | No fix yet |
| Red Hat Single Sign-On 7 | Affected | No fix planned: Out of support scope |
| Red Hat build of Apache Camel - HawtIO 4 | Affected | No fix yet |
| Red Hat build of Apache Camel 4 for Quarkus 3 | Affected | No fix yet |
| Red Hat build of Debezium 3 | Affected | No fix planned: Will not fix |
| Red Hat build of Quarkus | Affected | No fix yet: Fix deferred |
| Cryostat 4 on RHEL 9 | Fixed | RHSA-2026:68333 |
| Red Hat AMQ Broker 7.14.1 | Fixed | RHSA-2026:66488 |
| Red Hat Build of Apache Camel 3.33.2.SP3 | Fixed | RHSA-2026:48118 |
| Red Hat Data Grid 8.6.3 | Fixed | RHSA-2026:69296 |
| Red Hat JBoss Enterprise Application Platform 8.1 | Fixed | RHSA-2026:70421 |
| Red Hat OpenShift AI 2.25 | Fixed | RHSA-2026:65126, RHSA-2026:87410 |
| Red Hat OpenShift AI 3.4 | Fixed | RHSA-2026:84734 |
| Red Hat OpenShift Dev Spaces 3.30 | Fixed | RHSA-2026:62260, RHSA-2026:68754 |
| Red Hat OpenShift Dev Spaces 3.31 | Fixed | RHSA-2026:90321 |
| Red Hat build of Apache Camel 4.18.3 for Spring Boot 3.5.16 | Fixed | RHSA-2026:54622 |
| Red Hat build of Apicurio Registry 3.3.3 | Fixed | RHSA-2026:76637 |
| Red Hat build of Keycloak 26.4.14 | Fixed | RHSA-2026:50846 |
| Red Hat build of Keycloak 26.6.5 | Fixed | RHSA-2026:50848 |
| Red Hat build of Quarkus 3.27.4.SP3 | Fixed | RHSA-2026:47189 |
| Red Hat build of Quarkus 3.33.2.SP3 | Fixed | RHSA-2026:47172 |
| Streams for Apache Kafka 3.2.1 | Fixed | RHSA-2026:54435 |
Not affected: 10 products
- Cryostat 4 on RHEL 9
- Red Hat Build of Apache Camel 3.33.2.SP3
- Red Hat OpenShift AI (RHOAI)
- Red Hat OpenShift AI 2.25
- Red Hat OpenShift AI 3.4
- Red Hat OpenShift Dev Spaces 3.30
- Red Hat OpenShift Dev Spaces 3.31
- Red Hat build of Quarkus 3.27.4.SP3
- Red Hat build of Quarkus 3.33.2.SP3
- streams for Apache Kafka 2
Timeline
- 2026-10-02 Threatist record created from CVE-2026-56819
- 2026-10-03 Alias added: GHSA-93wv-jw9v-4972
- 2026-10-06 Affected versions changed · Red Hat
- 2026-10-09 Fix available: RHSA-2026:76637 · Red Hat
- 2026-10-09 Fix available: RHSA-2026:48118 · Red Hat
- 2026-10-09 Fix available: Red Hat Build of Apache Camel 4.18 for Quarkus 3.33, Red Hat build of Apicurio Registry 3.3.3 · Red Hat
- 2026-10-10 Fix available: Red Hat Build of Apache Camel 3.33.2.SP3 · Red Hat
- 2026-10-20 Fix available: RHSA-2026:84734 · Red Hat
- 2026-10-20 Fix available: Red Hat JBoss Enterprise Application Platform 8.1, Red Hat OpenShift AI 3.4 · Red Hat
- 2026-10-20 Fix available: RHSA-2026:70421 · Red Hat
- 2026-10-22 Fix available: RHSA-2026:87410 · Red Hat
- 2026-10-23 Fix available: RHSA-2026:50846 · Red Hat
- 2026-10-23 Fix available: RHSA-2026:50848 · Red Hat
- 2026-10-23 Fix available: Red Hat build of Keycloak 26.4.14, Red Hat build of Keycloak 26.6.5 · Red Hat
- 2026-10-29 Fix available: Red Hat OpenShift Dev Spaces 3.31 · Red Hat
- 2026-10-30 Fix available: RHSA-2026:90321 · Red Hat
- 2026-11-03 Affected versions changed · Red Hat
References
Patch 2
More Netty vulnerabilities
- TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
- TI-2026-30861 Netty: HTTP/1.0 TE+CL Coexistence Bypasses Smuggling Sanitization CVSS 3.1CRITICAL 9.8
- TI-2026-30864 Netty: HttpClientCodec response desynchronization CVSS 3.1CRITICAL 9.1
- TI-2026-30859 Netty: DNS Codec Input Validation Bypass in Netty (Encoder + Decoder) CVSS 3.1CRITICAL 9.1
- TI-2026-40973 Netty: Missing CertificateID Validation in OCSP Response Allows Replay Attacks CVSS 3.1CRITICAL 9.1
- TI-2026-40298 Netty SPDY SETTINGS frame count materializes unbounded settings map CVSS 3.1HIGH 7.5
Sources
- CVE-2026-56819 · CVE Program
- CVE-2026-56819 · NVD
- FIRST EPSS
- GHSA-93wv-jw9v-4972 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-56819 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences