Netty: HttpClientCodec response desynchronization
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · High
- Fix status
- Partial Red Hat: 21 fixed, 12 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat.
Summary
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpClientCodec pairs each inbound response with an outbound request by queue.poll() once per response, including for 1xx. If the client pipelines GET then HEAD and the server sends 103, then 200 with GET body, then 200 for HEAD, the queue pairs HEAD with the first 200. The HEAD rule then skips reading that message’s body, so the GET entity bytes stay on the stream and the following 200 is parsed from the wrong offset. This vulnerability is fixed in 4.2.13.Final and 4.1.133.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.Alpha1 to before 4.2.13.Final; before 4.1.133.Final | 4.2.13.Final, 4.1.133.Final | Patch available | CNA |
| netty | netty-codec-http | 4.2.0.Alpha1 to before 4.2.13.Final; before 4.1.133.Final | 4.2.13.Final, 4.1.133.Final | Patch available | CNA |
| — | io.netty:netty-codec-http (Maven) | 4.2.0.Alpha1 to before 4.2.13.Final | 4.2.13.Final | Patch available | GHSA-57rv-r2g8-2cj3 |
| — | io.netty:netty-codec-http (Maven) | before 4.1.133.Final | 4.1.133.Final | Patch available | GHSA-57rv-r2g8-2cj3 |
- netty Vendornetty Affected 4.2.0.Alpha1 to before 4.2.13.Final; before 4.1.133.Final Fixed in 4.2.13.Final, 4.1.133.Final Patch available CNA
- netty-codec-http Vendornetty Affected 4.2.0.Alpha1 to before 4.2.13.Final; before 4.1.133.Final Fixed in 4.2.13.Final, 4.1.133.Final Patch available CNA
- io.netty:netty-codec-http (Maven) Vendor— Affected 4.2.0.Alpha1 to before 4.2.13.Final Fixed in 4.2.13.Final Patch available GHSA-57rv-r2g8-2cj3
- io.netty:netty-codec-http (Maven) Vendor— Affected before 4.1.133.Final Fixed in 4.1.133.Final Patch available GHSA-57rv-r2g8-2cj3
Remediation
- Fix · CNA netty (netty) Fixed in 4.2.13.Final, 4.1.133.Final
- Fix · CNA netty-codec-http (io.netty) Fixed in 4.2.13.Final, 4.1.133.Final
- Fix · GHSA-57rv-r2g8-2cj3 io.netty:netty-codec-http (Maven) Fixed in 4.2.13.Final Advisory →
- Fix · GHSA-57rv-r2g8-2cj3 io.netty:netty-codec-http (Maven) Fixed in 4.1.133.Final Advisory →
Red Hat 22 advisories
- 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
- RHSA-2026:73976 Released 2026-09-30 · Red Hat rating ImportantRed Hat JBoss Enterprise Application Platform 7.1.16 security update
- Red Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7 Server eap7-hibernate-5.1.17-5.Final_redhat_00006.1.ep7.el7, eap7-hibernate-core-5.1.17-5.Final_redhat_00006.1.ep7.el7, eap7-hibernate-entitymanager-5.1.17-5.Final_redhat_00006.1.ep7.el7 +7
- RHSA-2026:73644 Released 2026-09-30 · Red Hat rating ImportantRed Hat JBoss Enterprise Application Platform 7.3.19 Update
- Red Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7 Server eap7-hibernate-5.3.39-1.Final_redhat_00001.1.el7eap, eap7-hibernate-core-5.3.39-1.Final_redhat_00001.1.el7eap, eap7-hibernate-entitymanager-5.3.39-1.Final_redhat_00001.1.el7eap +31
Show 19 more Red Hat advisories
- RHSA-2026:69459 Released 2026-09-21 · Red Hat rating ImportantAMQ Clients 2026.Q3
- AMQ Clients 2026.Q3
- RHSA-2026:66545 Released 2026-09-10 · Red Hat rating ImportantRed Hat AMQ Broker 7.13.6 release and security update
- Red Hat AMQ Broker 7.13.6
- 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-2026:54435 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-2026:53806 Released 2026-08-11 · Red Hat rating ImportantRed Hat JBoss Enterprise Application Platform 7.4.25 security update
- Red Hat JBoss Enterprise Application Platform 7.4.25
- RHSA-2026:53646 Released 2026-08-11 · Red Hat rating ImportantRed Hat JBoss Enterprise Application Platform 7.4.25 Security update
- Red Hat JBoss EAP 7.4 ELS for RHEL 9 eap7-activemq-artemis-2.16.0-22.redhat_00057.1.el9eap, eap7-activemq-artemis-cli-2.16.0-22.redhat_00057.1.el9eap, eap7-activemq-artemis-commons-2.16.0-22.redhat_00057.1.el9eap +47
- RHSA-2026:53645 Released 2026-08-11 · Red Hat rating ImportantRed Hat JBoss Enterprise Application Platform 7.4.25 Security update
- Red Hat JBoss EAP 7.4 ELS for RHEL 8 eap7-activemq-artemis-2.16.0-22.redhat_00057.1.el8eap, eap7-activemq-artemis-cli-2.16.0-22.redhat_00057.1.el8eap, eap7-activemq-artemis-commons-2.16.0-22.redhat_00057.1.el8eap +47
- RHSA-2026:53644 Released 2026-08-11 · Red Hat rating ImportantRed Hat JBoss Enterprise Application Platform 7.4.25 security pdate
- Red Hat JBoss EAP 7.4 ELS for RHEL 7 Server eap7-activemq-artemis-2.16.0-22.redhat_00057.1.el7eap, eap7-activemq-artemis-cli-2.16.0-22.redhat_00057.1.el7eap, eap7-activemq-artemis-commons-2.16.0-22.redhat_00057.1.el7eap +47
- RHSA-2026:49700 Released 2026-08-03 · Red Hat rating ImportantRed Hat JBoss Enterprise Application Platform 8.1.7 security update
- Red Hat JBoss EAP 8.1 for RHEL 10 eap8-eap-product-conf-parent-801.7.1-1.GA_redhat_00001.1.el10eap, eap8-eap-product-conf-wildfly-ee-feature-pack-801.7.1-1.GA_redhat_00001.1.el10eap, eap8-netty-4.1.135-1.Final_redhat_00001.1.el10eap +17
- Red Hat JBoss EAP 8.1 for RHEL 8 eap8-eap-product-conf-parent-801.7.1-1.GA_redhat_00001.1.el8eap, eap8-eap-product-conf-wildfly-ee-feature-pack-801.7.1-1.GA_redhat_00001.1.el8eap, eap8-jose4j-0.9.6-2.redhat_00002.1.el8eap +19
- Red Hat JBoss EAP 8.1 for RHEL 9 eap8-eap-product-conf-parent-801.7.1-1.GA_redhat_00001.1.el9eap, eap8-eap-product-conf-wildfly-ee-feature-pack-801.7.1-1.GA_redhat_00001.1.el9eap, eap8-jose4j-0.9.6-2.redhat_00002.1.el9eap +19
- RHSA-2026:49701 Released 2026-08-03 · Red Hat rating ImportantRed Hat JBoss Enterprise Application Platform 8.1.7 security update
- Red Hat JBoss Enterprise Application Platform 8.1.7.GA io.netty.netty-codec-dns-4.1.135.Final-redhat-00001.jar, io.netty.netty-codec-http-4.1.135.Final-redhat-00001.jar, io.netty.netty-handler-4.1.135.Final-redhat-00001.jar +2
- RHSA-2026:42644 Released 2026-07-21 · Red Hat rating ImportantRHOAI 2.25.9 - Red Hat OpenShift AI
- Red Hat OpenShift AI 2.25 registry.redhat.io/rhoai/odh-caikit-tgis-serving-rhel9, registry.redhat.io/rhoai/odh-feature-server-rhel9, registry.redhat.io/rhoai/odh-kserve-storage-initializer-rhel9 +36
- RHSA-2026:37390 Released 2026-07-09 · Red Hat rating ImportantRed Hat Build of Apache Camel 4.18.1.P1 for Spring Boot release.
- Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16
- RHSA-2026:36820 Released 2026-07-08 · Red Hat rating ImportantRed Hat OpenShift Dev Spaces 3.29.0 Release.
- Red Hat OpenShift Dev Spaces 3.29 registry.redhat.io/devspaces/code-rhel9, registry.redhat.io/devspaces/dashboard-rhel9, registry.redhat.io/devspaces/multicluster-redirector-rhel9 +6
- RHSA-2026:30049 Released 2026-06-25 · Red Hat rating ImportantRed Hat build of Keycloak 26.4.13 Security Update
- Red Hat build of Keycloak 26.4.13
- RHSA-2026:28010 Released 2026-06-22 · Red Hat rating ImportantRed Hat build of Cryostat security update
- Cryostat 4 on RHEL 9 cryostat/cryostat-openshift-console-plugin-rhel9, cryostat/cryostat-reports-rhel9, cryostat/cryostat-rhel9 +3
- RHSA-2026:25123 Released 2026-06-10 · Red Hat rating ImportantRed Hat OpenShift Dev Spaces 3.28.2 Release.
- Red Hat OpenShift Dev Spaces 3.28 registry.redhat.io/devspaces/dashboard-rhel9, registry.redhat.io/devspaces/openvsx-rhel9, registry.redhat.io/devspaces/pluginregistry-rhel9 +1
- RHSA-2026:24502 Released 2026-06-10 · Red Hat rating ImportantRed Hat build of Quarkus 3.33.2 release and security update
- Red Hat build of Quarkus 3.33.2.redhat io.netty.netty-codec-dns-4.1.133.Final-redhat-00002.jar, io.netty.netty-codec-http-4.1.133.Final-redhat-00002.jar, io.netty.netty-handler-proxy-4.1.133.Final-redhat-00002.jar
- RHSA-2026:23808 Released 2026-06-10 · Red Hat rating ImportantRed Hat build of Quarkus 3.27.4 release and security update
- Red Hat build of Quarkus 3.27.4.redhat io.netty.netty-codec-dns-4.1.133.Final-redhat-00002.jar, io.netty.netty-codec-http-4.1.133.Final-redhat-00002.jar, io.netty.netty-codec-http2-4.1.133.Final-redhat-00002.jar +1
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 planned: Will not fix |
| Red Hat Data Grid 8 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | Affected | No fix planned: Will not fix |
| Red Hat Fuse 7 | Affected | No fix planned: Will not fix |
| Red Hat JBoss Enterprise Application Platform Expansion Pack | Affected | No fix planned: Will not fix |
| Red Hat Process Automation 7 | Affected | No fix planned: Will not fix |
| Red Hat Single Sign-On 7 | Affected | No fix planned: Will not fix |
| Red Hat build of Apicurio Registry 2 | Affected | No fix planned: Will not fix |
| Red Hat build of Apicurio Registry 3 | Affected | No fix yet |
| Red Hat build of Debezium 3 | Affected | No fix planned: Will not fix |
| Red Hat build of OptaPlanner 8 | Affected | No fix yet |
| AMQ Clients 2026.Q3 | Fixed | RHSA-2026:69459 |
| Cryostat 4 on RHEL 9 | Fixed | RHSA-2026:28010 |
| Red Hat AMQ Broker 7.13.6 | Fixed | RHSA-2026:66545 |
| Red Hat AMQ Broker 7.14.1 | Fixed | RHSA-2026:66488 |
| Red Hat JBoss EAP 7.4 ELS for RHEL 7 Server | Fixed | RHSA-2026:53644 |
| Red Hat JBoss EAP 8.1 for RHEL 10 | Fixed | RHSA-2026:49700 |
| Red Hat JBoss EAP 8.1 for RHEL 8 | Fixed | RHSA-2026:49700 |
| Red Hat JBoss EAP 8.1 for RHEL 9 | Fixed | RHSA-2026:49700 |
| Red Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7 Server | Fixed | RHSA-2026:73976 |
| Red Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7 Server | Fixed | RHSA-2026:73644 |
| Red Hat JBoss Enterprise Application Platform 7.4.25 | Fixed | RHSA-2026:53806 |
| Red Hat JBoss Enterprise Application Platform 8.1.7.GA | Fixed | RHSA-2026:49701 |
| Red Hat OpenShift AI 2.25 | Fixed | RHSA-2026:42644, RHSA-2026:65126 |
| Red Hat OpenShift AI 3.4 | Fixed | RHSA-2026:84734 |
| Red Hat OpenShift Dev Spaces 3.28 | Fixed | RHSA-2026:25123 |
| Red Hat OpenShift Dev Spaces 3.29 | Fixed | RHSA-2026:36820 |
| Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16 | Fixed | RHSA-2026:37390 |
| Red Hat build of Keycloak 26.4.13 | Fixed | RHSA-2026:30049 |
| Red Hat build of Quarkus 3.27.4.redhat | Fixed | RHSA-2026:23808 |
| Red Hat build of Quarkus 3.33.2.redhat | Fixed | RHSA-2026:24502 |
| Streams for Apache Kafka 3.2.1 | Fixed | RHSA-2026:54435 |
Not affected: 13 products
- Cryostat 4 on RHEL 9
- Red Hat Build of Keycloak
- Red Hat JBoss Enterprise Application Platform 8.1.7.GA
- Red Hat OpenShift AI (RHOAI)
- Red Hat OpenShift AI 2.25
- Red Hat OpenShift AI 3.4
- Red Hat OpenShift Dev Spaces 3.28
- Red Hat OpenShift Dev Spaces 3.29
- Red Hat Satellite 6
- Red Hat build of Apache Camel 4 for Quarkus 3
- Red Hat build of Quarkus 3.27.4.redhat
- Red Hat build of Quarkus 3.33.2.redhat
- streams for Apache Kafka 2
Timeline
- 2026-10-02 Threatist record created from CVE-2026-42584
- 2026-10-03 Alias added: GHSA-57rv-r2g8-2cj3
- 2026-10-20 Fix available: RHSA-2026:84734 · Red Hat
- 2026-10-20 Fix available: Red Hat OpenShift AI 3.4, Red Hat build of Quarkus 3.27.4.redhat, Red Hat build of Quarkus 3.33.2.redhat · Red Hat
- 2026-10-21 Affected versions changed · Red Hat
- 2026-10-23 Fix available: RHSA-2026:30049 · Red Hat
- 2026-10-23 Fix available: Red Hat build of Keycloak 26.4.13 · Red Hat
- 2026-11-01 Affected versions changed · Red Hat
- 2026-11-06 Fix available: RHSA-2026:42644 · Red Hat
References
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-2026-30859 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-2026-40972 Uncontrolled resource consumption in netty CVSS 3.1HIGH 7.5
- TI-2026-40298 Netty SPDY SETTINGS frame count materializes unbounded settings map CVSS 3.1HIGH 7.5
Sources
- CVE-2026-42584 · CVE Program
- CVE-2026-42584 · NVD
- FIRST EPSS
- GHSA-57rv-r2g8-2cj3 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-42584 · 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